SharronP

Carbon Emissions from Gardening

In a previous article we explored ways that gardeners can lock up carbon in the soil. Although increasing soil carbon is important, it doesn’t address ways of dealing with greenhouse gases that are talked about less often, namely, methane and nitrous oxide. Fortunately, the approaches to reducing emissions of these gases also lead to better soil structure and fertility.

Methane

This gas, with the chemical formula CH_4, (i.e. each molecule contains one carbon atom) is worrisome because it is 25 times more potent than carbon dioxide in its global warming impact, weight for weight. However, it decays more rapidly in the atmosphere than carbon dioxide. It is produced naturally from wetlands and as a result of the digestive processes of ruminant animals (cows and sheep). It also leaks from natural gas systems.¹

The major pathway for methane to be generated by gardening activities is through breakdown of organic matter in anaerobic conditions i.e. when oxygen is excluded. Gardeners may cause extra methane to be added to the atmosphere by some methods of composting and making weed “tea”, soil compaction and poor pond maintenance.

Composting

We all want compost, don’t we? But significant amounts of methane can be produced in the centre of compost heaps as material is broken down and the temperature rises. Methane production appears to be due to the density of the heap so that oxygen cannot penetrate and anaerobic microorganisms are favoured. To reduce this problem the heap needs to be well aerated. You can do this by:

Making your own compost bin or bay out of material that lets air through i.e. not solid plastic. Suitable materials are timber slats, logs or trellis or chicken wire.
Building the heap with a wooden pallet as the base. This gives some air space under the heap.
Adding material such as straw that doesn’t get compacted so easily.² Make sure that there are plenty of dried leaves, twigs and other fibrous materials in the heap. These are best added in layers with the amount of dry material about equal to the amount of wet/green.
Including vertical aerating tubes as you build the heap. These can be made from tightly rolled chicken wire or PVC pipe with lots of holes drilled into it. Such devices have the added advantage of making it easy to get water into the centre a heap which is drying out.
Using a tumbling device.
There are a number of different designs for tumblers commercially available. If these are rotated every day or so, they will aerate material satisfactorily. However, they sometimes lead to lumps which can get aerobic, if enough dry material is not added at the same or, indeed, mixed with the wet material before adding it. Actually turning the tumbler can be a problem since it can get quite heavy.
For a thorough coverage of managing a tumbler see www.the-compost-gardener.com/composting-tips.html
If all else fails, you can engage in some physical exercise and turn the heap regularly. You can do this with a garden fork (easier than a shovel), but it can be backbreaking work. There are various compost turning tools available now, such as one which looks a bit like a large corkscrew. It twists down easily and then you can pull out a plug of material from further down the heap.

Making weed “tea” under anaerobic conditions

Here is a dilemma. In a previous article we explored how to make compost, worm and weed teas to produce soluble fertilizer and discussed how the solid material needs almost constant stirring to avoid anaerobic conditions. We also pointed out that it may be easier for home gardeners to use the anaerobic method with only occasional stirring. Given that this method favours methane production, you might have a bit of a debate with yourself about the relative costs and benefits of each method or choose other ways of processing garden waste such as solarizing or composting.

Compacting soil

This happens by placing heavy weights on it e.g. heavy machinery or walking. Compaction removes the air spaces which aerobic microorganisms need for their oxygen supply. It is less likely to happen in raised garden beds and if the bed width is limited to about 1 metre so that you can reach across.

Pond Maintenance

Ponds can become anaerobic if the water gets very murky or if the surface gets too much growth of water weeds such as Azolla³ as in the image on the right. These conditions can limit light entry so that submerged oxygenating plants are killed. Adding unsuitable fish species which stir up sediment can have a similar effect.

Nitrous oxide

Although it does not contain carbon atoms, nitrous oxide, N₂O, is 298 times more potent as a greenhouse gas than carbon dioxide, but is shorter lived, persisting in the atmosphere for 114 years. So we should not just think about carbon emissioins from gardening!

It has been calculated that 40% of emissions of this gas in the USA come from human activities with about 70% of that derived from agricultural land management. Nitrous oxide also happens to be the most important gas contributing to the hole in the ozone layer now that halocarbon levels are declining.

To reduce extra nitrous oxide being emitted we can:

Use manures and other organic sources of nitrogen rather than synthetic nitrogen fertilisers and apply them carefully so that there is not excess nitrogen for plant use – that means not applying them when plants are not actively growing. Synthetic nitrogen fertilisers also contribute to making soil more acid.
Since acid conditions encourage biochemical pathways that produce nitrous oxide, if soil pH is low we can add lime or dolomite.
Use no-dig methods to avoid soil disturbance.
Turn garden waste into compost or mulch rather than burning it.
Avoid working soil when it is wet as this assists compaction which creates conditions in which soil micoorganisms convert nitrates to nitrous oxide.

References

Reay D, Smith P, van Amstel A. 2010. Methane and Climate Change. London: Earthscan. ISBN978-1844078233.
Sommer SG, H. B. Moeller. 2000. Emission of greenhouse gases during composting of deep litter from pig production – effect of straw content. 2000. J. Agricultural science 134 (3) 327-335.
Rachel A, Janes JW, Eaton K . 1996. The effects of floating mats of Azolla filiculoides and Lemna minuta Kunth on the growth of submerged macrophytes. Hydrobiologia 340 (1) 23-26.

by SharronP

Compost, Worm and Weed Teas

If you are a gardener who tries to reduce your impacts on the natural environment, you will be using methods which avoid manufactured fertilisers, pesticides and herbicides and which minimize waste. So you’re into composting and worm farming and mixing the resulting solid material into the soil. However, at many times of the year a liquid fertilizer in the form of a “tea” may give plants, especially vegetables and fruit trees, a boost that is quicker than applying the manure, worm castings or compost which release their nutrients much more slowly. Such teas can be made from compost, weeds and other greenery and manures. How do you make and use them? What are their pros and cons?

The advantages of using teas are said to be:

They provide nutrients for you plants more quickly in the soil than the solid material used to make them.
The microbes in them make soil nutrients available and help prevent soil and plant diseases, something that commercial fertilisers do not do.
They are cheaper than commercially manufactured fertilisers.
Unwanted plant material in your garden can be turned into something really useful.
They make the garden more self-sufficient by recycling material it has produced.

On the other hand, because the effect of teas depends on the quality of the starting materials, how the teas are made, the climate, when they are applied, the plants they are used on and the state of the soil before their use, there is debate about their usefulness, with some findings that they can be harmful.

Extracts and teas

Don’t confuse extracts and teas. The simplest, but not the best, method of making a liquid fertiliser from your garden material is to make an extract. This is made by covering some compost, worm castings or manure with water for a few hours or days. Nutrients and minerals from the solid materials dissolve in the water and microorganisms present on the solids can enter the liquid. This can then be used by either applying directly to the soil or, when diluted to the colour of weak tea, as a foliar spray. However, these extracts are inferior to teas which have been brewed.

Why bother making a tea?

If properly brewed, teas provide much more than minerals and other nutrients. They are also very rich in microorganisms, a mixture of bacteria, fungi, protozoa and nematodes, which can fight plant disease-causing organisms in the soil and on foliage and can convert soil nutrients into forms that can be taken up by plants. They usually take longer to make than extracts and may involve more effort. For many gardeners and organic farmers, making compost tea is both a science and an art. And there are many different opinions about what method is best and, indeed, whether they work at all.

Compost tea

To prepare compost tea, put mature compost into a container like a bucket or plastic rubbish bin. You can put compost straight into it or into a “bag” which can be made from a piece of shade cloth or other material with small holes like old net curtains, stockings of panty hose. Cover the compost with water. It is preferable to use rain water, filtered water or mains water that has been allowed to stand for 24 hours to allow the chlorine to off-gas before adding to the weeds. The removal of chlorine makes it easier for microorganisms to multiply. You will need to add something to start the process off by providing easy to access nutrients for microbial growth. The best additions are brown sugar or molasses but others could be some fish meal, some canned fish which has been allowed to “go off”, grain meal, fish food, rotten fruit, compost, garden soil or finished compost. Nitrogen rich vs sugar rich additions give different results in terms of favouring bacteria or fungi.

Then there are two ways you can brew the tea:

Aerobic

This requires aeration. This process provides oxygen which allows aerobic microorganisms to multiply rapidly and break down the plant material. You could use a stick, which means you will need to stir it several times a day for about 10 days. In between stirring, cover the bucket or bin loosely so that air can enter. But unless you really like physical exercise and can remember to stir each day, using a fish tank aerator for about 3 days is a good alternative. There are many websites which provide ideas for you to make your own compost tea aerator, and there are even some commercially available assemblies.

Tea made this way will not smell unpleasant and should be used straight away. There are different opinions about how long the tea should be brewed. It really depends on your compost, the temperature and the nature of aeration. At some point, aerobic microorganisms will have used available nutrients and not be getting enough oxygen, so anaerobic microorganisms will take over. At this stage it will start to smell wiffy – but don’t despair. You can use it quickly before the aerobic microbes all die (because there will always be a few aerobic microorganisms) or let it go on brewing under anaerobic conditions.

Anaerobic

Some practitioners recommend that it might be better for home gardeners to use the easier anaerobic method which does not involve aerating and favours microorganisms which do not require oxygen. Just cover the container fairly firmly and wait for about 3 weeks. It requires longer and tends to be smellier but still produces a useful product. Some say that after the anaerobic microbes have finished, aerobic ones will take over again. But as I indicated, there is some controversy over this.

Worm tea and worm farm leachate

Most of us are also familiar with the liquid that comes out of the worm farms – called names such as worm wee, worm juice or worm tea, but really is a leachate. It contains plant nutrients, but is not rich in microorganisms like compost tea. Worm leachate really needs to be used cautiously since it contains “bad” bacteria as well as “good” and may be harmful to plants, especially if it smells “off”.

For worm tea, the castings from a worm farm can replace compost in the teas described above.

Weed tea

The best weed tea is made from plants with deep roots like comfrey, dandelion and nettle since they have incorporated minerals that have been leached from topsoil. Making weed tea is also a great way of extracting nutrients from plant material you don’t want in either your garden or in your compost heap where they would start multiplying. It also includes plants with runners and those which take root easily.
Follow the methods described for compost tea but it may be necessary to weigh the weeds down between stirring because they may float.

Manure tea

Animal manure can be used to make a tea by the same methods as for compost tea. However, there is a high risk of producing a brew which contains organisms which can be harmful to both plants and humans, especially if it is anaerobic. An extract, however, is a quick way making a nutrient-rich solution, but it will not have the same benefits as a microorganism-rich aerobic tea.

Using teas

Remove the bag which contains the solids and let it drain into the container. Or if you haven’t used a bag, pour the liquid through some shade cloth or other fine material laid in a soil sieve. It would be wise to do this wearing rubber gloves (and perhaps a peg on your nose!) since this might be a pretty potent and smelly brew. Put the solid material into your compost heap where it will break down further.

Remember, teas contain living organisms and should be treated with respect. Sun and heat can kill them, so apply them to the garden early in the morning or after dusk. The most useful times of the year to use them appear to be early spring, several times during the growing season and towards the end of autumn so that the organisms can work in the soil over winter.

Handle the brews carefully with gloves and don’t apply to vegetable leaves that will be eaten, especially if anaerobic and smell bad, since it is possible that pathogenic organisms are present. Use the tea diluted one to ten as a foliar spray, or less diluted if applying to soil.

And don't expect miracles - results depend on so many factors that they are impossible to predict. We'd be interested in hearing of your experience.

References

Lowenfels J and Lewis W. (2010) Teaming with microbes. Timber Press, Portland, Oregon.
What are the Benefits of Aerated Compost Teas vs. Classic Teas? http://faq.gardenweb.com/faq/lists/organic/2002082739009975.html
Secrets of Making Compost Tea.www.compostjunkie.com/making-compost-tea.html

by SharronP

Gift Ideas for Sustainable Gardeners

If you're like me, come the beginning of December, I'm scratching my head to think of suitable presents that might be appreciated by the recipients. Even if I'm giving to someone who isn't really a gardener or not particularly interested in sustainability, it feels better to give something that I know is not just going to add further pollution to the world, but something that might improve it a bit. So here are some ideas - some are more suitable as gifts for avid sustainability devotees, but others could be given to anyone.

Gardening Gifts

Recycled planter

Although an obvious gift for a gardener is a plant of some sort, why not make it more special by supplying it in a container that is made from something recycled and is also decorative. It could be something simple and home made, as in the image on the right or it could be something more decorative and perhaps bought from a store.

Seeds

Avid gardeners are always pleased to receive seeds, especially if they are heirloom varieties. This type of seed, obtainable from specialist seed suppliers, enables preservation of old genetic types that are being lost as large seed companies breed types that are quick to grow in order to please a mass market. Many of the newer seeds arise from cross-breeding of 2 different varieties to yield plants with particular characteristics e.g. colour or vigour. If seed from that type of plant is saved and subsequently sown, there may be no offspring at all, or, if there are, the offspring will not be like the parent plant. In contrast, plants grown from heirloom seeds will produce fertile seeds which can be saved and used to grow the same plant in subsequent years. So gifts of such seeds are gifts that "last" years.

You could even save seeds from your own heirloom plants, put them in attractive packets which you could also make yourself out of recycled paper - there are templates and instructions on various website.

Plant Labels

Gardeners need to identify what seeds they have planted in either pots or in the ground. A great gift would be a set of these made from either plastic or wood. Perhaps accompanied by a weather-resistant marker pen.

Watering Can

In my experience, watering cans can wear out, especially if they are left outside or used a lot. Some can rust or the the screws attaching the handle can fall out. Plastic watering cans suffer from sun damage and have a limited life. Most gardeners find that having more than one is very useful. Look out for good quality examples or those that are decorative. Or you could paint designs on one yourself.

Insect hotel

These creations, also called insectaries, provide somewhere that beneficial insects can shelter in the garden can serve as a garden decoration as well. If you don't know about them see our article which also shows some different designs. You could make one like the example on the right, yourself - from a strip of heavy duty fabric e.g. shade cloth, with pieces of hollowed out wood packed inside. Bamboo is a useful material since it already has hollows, but it is easy to drill holes in other materials. Providing insect shelters like this are a great way of keeping control of the nuisance bugs.

There are also designs that provide shelter from harsh weather (wind and rain) for butterflies. They usually have long vertical slits instead of round holes.

Such "hotels" are also available commercially - just do a web search. But it is worth reading up a bit on good design and materials to use. Since SGA's article was written, these "hotels" (also called insectaries) have become quite popular and there is some excellent online advice on how to maximise their insect-friendliness.

Nestbox

Shelter for bigger critters could also make an excellent gift. They can offer places for birds, microbats, ringtail possums or sugar gliders. There are different designs for the different animals and birds. You'd best check out what creatures are in the area and, of course, if the recipient want those creatures in their garden. Check out some advice here.

Compost bin or worm farm

Since compost bins or worm farms are excellent ways of turning waste into "black gold" for the garden, they make wonderful gifts. Of course, check first if your recipient has one already.

Tools or Clothing

There many garden tools which gardeners need. Giving them as gifts mean you can buy higher quality than gardeners might for themselves:

secateurs
lopper for difficult pruning branches thicker than those that secateurs can cut
a really lovely and long lasting stainless steel hand trowel or hand fork
long lasting scratch-proof garden gloves
pruning saw
knee pads that strap on
too carrier - either a tool belt/apron to wear around the waist or a caddy to carry.

Other Ethical Gifts

If your special person is not a gardener but you are, there are a number of other gift items that have reduced environmental or social impacts. There are now - at last! - dozens of ethical gift opportunities. These include:

soaps and hand wash made from natural or organic materials
fair trade products
organic food products e.g. natural honey

Reusable Beeswax Food Wraps

This is an idea that particularly attracted our attention. These food wraps are a colourful, durable, washable alternatives to plastic bags for packing snacks, sandwich lunches or fruit for the person on the go, and can also be used for storing food in the fridge or pantry. Available from several manufacturers, they are usually made from organic cotton and coated with beeswax blending with natural resins. There is even online advice on how to make your own.

Enjoy making or buying these gifts for your special people!!

by SharronP

New Book "Tomato"- All Your Questions Answered and More

Tomato – Know, Sow, Grow, Feast, 2018

This new book by Penny Woodward, Janice Sutton and Karen Sutherland makes a major contribution to providing tomato-lovers with all you need to know to choose the right varieties of this wonderful fruit, to grow them and to use them.

A request by Margot White of the Royal Tasmanian Botanic Gardens to Penny to write a book about tomatoes for the 200th anniversary of the gardens was the initiator of this book. Margot and Friends of the gardens collected and grew tomatoes from all over the world with assistance of tomato groups and breeders. The resulting collaboration between her and the three knowledgeable authors has yielded a book replete with information and hundreds of beautiful photographs of all types of tomato, with a special emphasis on heirloom varieties – and the book covers 223 of them! Photos also illustrate every section of the text from sowing, planting, the different varieties to pests and growing problems. And the photos accompanying the many recipes will inspire you to try different ways of tempting your palate.

If you wish to choose heirloom tomatoes to grow, you could choose them on the basis of their benefits to health, their appearance, your local climate characteristics or what recipes they are best suited for. There are red, pink, yellow, orange, white, green, purple and brown, blue/black or striped, blushing or swirls.

For some, particular health benefits may dictate choice - the higher dietary intakes of the chemical that gives tomatoes their red colour, lycopene, is associated with reduced risk of prostate cancer and cardioivascular health. The yellow colour of yellow tomatoes is partly a result of their lutein content and is known to help slow development of cataracts and macular degeneration and may be important in maintaining cognitive function as we age. Lutein is also present in orange and green tomatoes as well as some other yellow or green vegetables.

And then you might choose varieties because they are particularly suitable for certain culinary uses.

The different heirloom varieties are all described in terms of their appearance, flavor, history and sellers of seed (some shown in the image on the right) . There is also a handy guide to varieties suited to particular climates, withstanding disease or to the growing space you have available.

The section on growing tomatoes covers soil preparation, sowing, transplanting, spacing, pruning, grafting and water and fertilizer needs. The authors have provided an extract for SGA from pages 19 – 21 on liquid feeds. Here Karen Sutherland lists a range of options – some of them might surprise you! Those suitable for vegans are shown as V:

“Liquid feeds provide an immediate benefit to your plants and are useful as an adjunct during rapid growth stages, or when flowers and fruits are forming, to more slowly released nutrients already in your soil. They also improve soil microbial activity, helping plants take up nutrients more successfully. It’s best practice to water soil before and after applying any fertiliser, including strong liquid feeds. If making homemade liquid feeds in a plastic rubbish bin or bucket, ensure your container has a close-fitting lid to avoid mosquitoes. As a general rule, all homemade liquid feeds should be diluted to the colour of weak tea before using.

Worm tea – Also called worm wee and worm leachate, this is made from the liquid that drains out of the bottom of worm farms and will reflect the quality and make-up of what is fed to the worms. Dark brown in colour when it first emerges, once diluted it is safe to use on plants and highly beneficial.

Compost tea – Mix compost, water and molasses, and then aerate with an aquarium bubbler for three days. Due to the bubbler, the container holding this mixture does not require a lid. Put the compost inside an old pillowcase to avoid blocking the bubbler. The aeration multiplies natural microorganisms in the compost, resulting in a liquid that supplies nutrients and also improves soil microbial activity. Use ½–1 part compost to 4 parts water and a teaspoon of molasses per 4L of tea. V

Liquid seaweed – Although not a complete fertiliser, as it’s low in nitrogen and phosphorous, liquid seaweed contains valuable trace elements (iodine and potassium) as well as growth stimulants. It’s a great tonic to encourage plant growth and thicken plant cell walls, giving plants greater resistance to the extremes of heat and cold now so common in our altered climate. Use every two weeks and at transplanting to help with transplant shock. V

Fish emulsion – Generally contains a NPK ration of 5-2-2. Can be applied fortnightly and mixed with seaweed solution. Check labels for appropriate rates, and apply when soil is moist so that nutrients are accessible to plants.

Homemade weed teas – These can be made from the weeds you clear from your own garden. Fill your container loosely with freshly pulled out weeds, and cover with water and a lid. After three days, most nutrients will have gone into the water and the weed tea can be used. Strain the liquid into a watering-can, and use diluted to fertilise tomatoes weekly. This allows the nutrients in the weeds to be retained on-site and used in the garden more quickly than if the weeds were added to compost. It also allows the nutrients in perennial weeds to be used rather than lost to green bins. Rotted weeds can be added to your compost after using the tea, although perennial weeds may need an additional soaking to ensure they are rotted and can’t regrow. V

Specific weed teas – Some weeds have particular qualities that are worth introducing to your garden. The best plants for weed tea are those that have a long taproot and can seek out nutrients from deep in the soil. In permaculture, these plants are known as ‘dynamic accumulators’, as they store nutrients mined from the subsoil in their leaves; these nutrients can be made available to other plants through decomposition. Plants considered to be dynamic accumulators are comfrey, dandelion, nettle and plantain. V

Homemade manure teas – This enables the use of manures that would otherwise be problematic due to the weed seeds they contain, such as horse manure. If the tea is well made, the nutrients from the manure are retained, the weed seeds rot and the residue can be added safely to your compost. Tie the manure inside an old pillowcase to make a giant manure tea bag, and steep it in your container of water. After around three days, remove the manure to your compost and use a watering-can to distribute the manure tea on your garden bed, avoiding leaves.

Molasses – It’s not used for feeding plants directly, but because it promotes good microbial activity in the soil. This helps plants take up nutrients so they become healthier, stronger and more resistant to pests and diseases. Mix 100ml of molasses with a small amount of hot water to dissolve it, then stir the mixture into 10L of water and sprinkle it liberally over the soil. Use it once or twice per season only. V

Milk – Use it undiluted on the soil before planting, or added to compost to improve microbial activity, or utilise it as a foliar feed in the ratio of 1 part milk to 5 parts water. Studies on using milk to feed the soil are relatively new, but they show that approximately 1ml/m2 milk applied to soil improves crop yields and that raw milk may be the most effective. Certainly any milk past its use-by date in your fridge is better on your garden than down the sink. Skim milk is as effective as whole milk, and cheese-making by-products such as whey are also beneficial.

Banana skin tea – Lina Siciliano has come up with a novel liquid feed. Knowing that banana skins contain a lot of potassium, she reasoned that they could be made into a fertiliser by soaking them in water. She puts 20 skins into an old orange or onion bag, places the bag into her 10L watering-can, fills it with water and covers the opening. After 10 days, she uses the liquid straight (as long as it’s the colour of weak tea) or diluted, either weekly or fortnightly. Lina finds that her tomato plants flower better and grow tastier fruits when she uses this feed. V”

The extensive “Feast” section will delight both gardeners and cooks. It covers storage and preparation methods, how the varieties differ in flavor and texture, preserving methods and recipes for fresh tomatoes. As well as recipes for tomato sauce, pickles and sun-dried tomatoes, there is an excitingly large range of dishes where tomatoes are included with fish or other ingredients. The soups such as Creamy Roasted Tomato + Squash, Bush Tomato or Tomato and Cherry Gaspacho sound delectable. And you can even read how to make Bloody Mary and Tomato + Basil icecream!

by SharronP

Gardening the New Health App

At the combined 2018 SGA Annual General Meeting and the October meeting of SGA's Green Gardening Professionals, Paul West, well-known from the SBS TV program River Cottage gave an inspiring talk about gardening and how it can make us, and keep us, healthy.

https://youtu.be/AIcGXpTHl3k

by SharronP

Summer Series of Talks

Christmas is approaching, and SGA has a great gift idea for that special gardener in your life. Or maybe it’s a perfect gift to give yourself.

For the first time SGA is running a Summer Series of 7 gardening talks over 7 weeks. This series will kick start the gardening year and is for all gardeners, from novice to experienced. Attendees will come away with inspiration, new ideas and projects for the garden that will also help the environment.

Every Thursday evening at 7pm from 17th January 2019 to the 28th February 2019 we will be hosting a 45 minute talk followed by Q&A time and a cuppa, in the beautiful surrounds of Edendale Community Environmental Farm, Eltham.

The Summer Series can be booked as a package or as individual talks of your choice. If choosing an individual topic is too hard, why not buy a Gift Voucher and let the receiver of your gift make the choice?

We have worked out some very special Christmas Present prices for you.

• The complete Summer Series of 7 talks for only $122. A 30% Christmas discount
• A single talk for only $20. A 20% Christmas discount

The gift of a single talk makes a perfect small present or Kris Kringle gift.

Buying Tickets

Tickets can be bought at the Summer Series Booking Page. From the main booking page, you can buy tickets for the whole series, or if you only want to buy tickets for specific talks, you can link to the individual event booking pages pages via the headings for each talk.

Gift Vouchers

Gift vouchers can be purchased in any of the booking pages. The gift voucher link can be found near the top of the booking page, near the social media icons. You can choose the value of the gift vouchers and it will be valid for any SGA workshop or talk.

Sample Booking Page

What is on Offer

Full Summer Series Package - All 7 Talks over 7 Weeks - Thurs 17 Jan - Thur 28 Feb

This summer series is a great way to start the new year in the garden. Learn about growing healthy food without use of harsh chemicals - how to increase the biodiversity of your garden, inviting in birds and bugs and using indigenous plants. About the food, fibre and medicine properties of some of our indigenous plants. How to use water resources wisely, reduce waste and reuse materials in your garden.

Talk 1. Water Smart Gardening - Thursday 17 Jan 19

Water is critical to a garden’s success. As we experience hotter and dryer summers, we need to be mindful about how we use water still while helping our gardens to thrive.

In this talk Richard will discuss design, maintenance and watering options for you to consider at home that will help reduce water usage while supporting a healthy and productive garden.

Talk 2. Garden Pests – A Dance with Nature - Thursday 24 Jan 19

Your garden is the home for many types of insects – the Good, the Bad and the Ugly.

In this talk Richard will look at how to use nature to strengthen the balance within your garden allowing you to minimise unnecessary chemical use. We will discuss mechanical, cultural, biological and low impact chemical controls to help you manage your garden pest problems.

Talk 3. Attracting Birds to your Garden - Thursday 31 Jan 19

The variety of birds attracted to our urban gardens seems to be decreasing but there are some simple changes you can make to your garden to make it a more inviting habitat to visit.

In this talk Richard will discuss how to change your garden and invite birds to take up residence once again. He will cover the fundamentals of a habitat garden incorporating the important habitat elements of food, water, shelter and nesting places.

Talk 4. Indigenous Plants for Food, Fibre and Medicine - Thursday 07 Feb 19

The Australian bush provided the first nations people all the Food, Fibre and Medicine needed to thrive in this unique country.

In this talk Richard will introduce you to some of the local plants used by indigenous Australians and inspire you to grow them in their garden.

Talk 5. Preparing your Garden for Autumn Harvest - Thursday 14 Feb 19 - Valentine’s Day

While summer is at its peak and its too hot to go outside in the garden, spend some time planning your veggie garden for the autumn harvest.

In this talk Nicole will cover autumn maintenance activities, what veggies to plant and how to help them produce a bumper harvest.

Talk 6. Garden Weeds – A Dance with Nature - 21 Feb 19

Weeds are the bane of the home gardener but also a serious threat to local native flora and fauna. Weeds compete with preferred plants for space, light, nutrients and water and often are designed to win the battle.

In this talk Nicole will cover identifying and control weeds using an integrated approach that minimises negative environmental impacts. She will also talk about edible weeds.

Talk 7. Thrifty Gardening – Reduce, Reuse and Recycle in the Garden - 28 Feb 19

Waste is a growing environmental challenge that we can all do something about. Remember, there is no waste in nature and we can apply this thinking to our own lives and gardens.

In this talk Nicole will inspire you to use more recycled materials in your garden, helping the environment while making your garden more beautiful, unique, functional and productive.

The talks will be presented by two of SGA’s passionate trainers.

Richard Rowe

Richard is a passionate home gardener, worm farmer, experienced trainer and community facilitator. After a long and successful corporate career in finance and sustainability, Richard now focuses on environmental education for both adults and school children and on the local food movement.

Nicole Griffith

Nicole is a qualified teacher with over ten years of experience as an educator and presenter. She has a particular interest in edible gardening and has worked with both school and community kitchen garden programs

by SharronP

Should I Use Sphagnum or Peat Moss?

Have you ever been confused about what is in a garden product? Here’s a prime example!

For many years, peat moss and sphagnum moss have been staple components of potting mixes and a useful addition to garden beds. More recently, however, a number of concerns have been raised about their use – harm to irreplaceable environments, increased carbon emissions and more. But working out what you are actually getting when you buy a product with ‘peat’ or ‘sphagnum’ in the name can be tricky. Let’s try to unravel the story.

Both sphagnum moss and peat moss are used in gardens as soil amendments for a number of reasons:

their low pH means that they are useful for camellias, azaleas and other acid loving plants,
they can hold water up to 20 x their weight,
they generally lack weed seeds and pathogens,
their ability to easily absorb and release some mineral ions,
their high porosity allows penetration of fine roots.

They are especially valued for growing mushrooms and for the air layering method of plant propagation.

What are They?

Peat is formed from decomposition of sphagnum moss and other organisms over many thousand years. There are more than 370 species of sphagnum which may form peat which accumulates in cool, moist climates in wetlands or lakes which turn into bogs. It is mainly found in the northern hemisphere – Canada, northern Russia, Scandinavia and Scotland - and, in the southern hemisphere, in New Zealand, Tasmania, Argentina and Chile. Small areas occur in south-Eastern Australia between 300 and 1500 metres altitude.

Peat bogs and wetlands are fragile ecosystems occurring only where moisture conditions are right and, therefore, host a unique variety of fauna and flora.

Peat and sphagnum moss are harvested by mining either by machinery or, traditionally, by hand. Networks of ditches are dug so that water drains out. The bog then dries out and the moss dies. Surface vegetation is removed and the upper layers allowed to dry in the sun before being vacuum harvested or removed by other methods. Peat/moss is put into large bales and removed from the site either by vehicles or by being dragged.

Peat has also been harvested for use as fuel, particularly in the northern hemisphere, contributing to peat bog destruction. In Finland, for example, only 40% of peat lands remain.

What are the Environmental Consequences of Peat and Sphagnum Moss Harvesting?

Change and Loss of Fragile Habitats

Moss may start regenerating, but very slowly, if at all, since the ditches and vehicular movement have changed the pattern of water flows so that conditions are no longer suitable for moss growth. This allows other vegetation, such as sedges, to invade the site displacing the indigenous species.

Methane and Carbon Dioxide Release

Changes in water flows which direct water away from the bogs are perhaps the most dangerous result of peat harvest since they also cause extensive drying of the peat with accompanying release of methane. Lightening strikes can ignite it and sometimes auto-ignition occurs when other flammable gases are present. The results are huge underground fires which may burn for many weeks, as occurred Indonesia and Spain, releasing large amounts of carbon dioxide¹– something our planet does NOT need to happen. Currently a peat bog in south western Victoria is burning. The resultant ash cloud and other gases released are endangering the health of nearby residents.

“Resource” Depletion

Continued formation of peat is threatened by global warming, as well as extensive mining, since drying out of the top layer kills the sphagnum moss layer above the decomposing material. Because it takes such a long time for peat to form, mining it means depleting an almost non-renewable resource.

Conservation Measures

In Australia, peat lands are given varying degrees of protection, ranging from threatened in Tasmania to endangered under the Environment Protection and Biodiversity Conservation Act 1999 for the whole of the country, Victoria and relevant parts of NSW.

Sustainable Harvesting?

Listing of sphagnum moss as endangered in Tasmania means that controlled harvesting is permitted. A Code of Practice sets out clear conditions which exclude a number of sites and include maintaining at least 30% cover.²

Garden Products for Sale

This is where much confusion lies. In North America, sphagnum is called 'sphagnum peat moss' while in Britain it is more often 'sphagnum peat'.

In Australia, a number of products containing different versions of these mosses are available and the names are confusing!! While their garden properties are fairly similar, their environmental impacts are rather different, and if you want to tread lightly on the planet you need to read the labels carefully.

Peat Moss

This term seems to be used interchangeably with 'Sphagnum Peat'. We could only find one source where harvest is “sustainable”. Otherwise it is probably obtained from deep in peat bogs.

Sphagnum Moss

Some suppliers use material from Canada or New Zealand where moss growing on top of the bog is picked by hand and then loaded into helicopters in an attempt to avoid damage to the bog. In some cases it is claimed that the moss is “farmed”. There are also products from New Zealand where harvesting is claimed to be sustainable. However, watch out for other products where there is NO information about the source material.

Blonde peat moss

There are at least 2 suppliers of blonde peat moss. It is a lighter colour than peat moss because it is sourced from the top 2 metres of the peat bog. There is no information about methods of harvesting, but material from this depth almost certainly required heavy machinery use with accompanying environmental damage.

Coir Peat – a Sustainable Alternative

This is not peat derived from sphagnum moss. Sometimes called ‘Coco Peat’ or ‘Coconut Coir’, it is fibre from between the outer shell of coconuts and the inner material used for food. It has similar properties to sphagnum peat with respect water holding capacity, but may have higher levels of salts if they have not been previously extracted. Its pH is closer to neutral so does not acidify soil as does sphagnum moss.

So, since coir is a renewable resource, does not endanger fragile environments or contribute to global warming, it is a much better alternative as a soil amendment than even ‘sustainably harvested’ sphagnum moss.

References

Lim, Xiao Zhi (2016). Vast Peat Fires Threaten Health and Boost Global Warming (2016). https://www.scientificamerican.com/article/vast-peat-fires-threaten-health-and-boost-global-warming/
Tasmanian Government (2016). Sphagnum Moss - Sustainable Use and Management. http://dpipwe.tas.gov.au/conservation/flora-of-tasmania/sphagnum-moss-sustainable-use-and-management

by SharronP

Is Your Tea Sustainable?

Tea has been a favorite beverage of many cultures for centuries. Drunk originally in China for medicinal purposes it is now mainly drunk to get a 'lift'. But there are now dozens of different teas from many plant sources and all come in different types of packaging, loose, in cans or boxes or in little bags. We can also grow teas at home – even in Australia. These different methods of obtaining tea differ in their sustainability and maybe grow-your-own is best.
he early 1600s. Its use then spread to France, Germany and Great Britain in the mid-1600s. Initially only drunk by the wealthy because it was expensive, it became more widely used when more was imported and the price fell to the point where it could be regarded as a typically British beverage².

Growing Tea

Most tea production has been in humid areas with rich, acid soil and high rainfall. It grows well in tropical and sub-tropical climates with partial shade, but in other areas it needs full sun as long as it receive sufficient water. Pesticides are used in many tea-growing areas³, but their levels are reduced in the final products if the tea leaves have been washed during processing.

In Australia, tea is grown in many regions from north Queensland through to Victoria and Tasmania^4,5. It has an advantage that it does not need pesticides because Australia’s quarantine regulations have prevented pest entry.

Nerada in far north Queensland is perhaps the oldest tea company - the Cutten family commenced growing tea in 1886⁶.

Unfortunately, cyclones and a tidal wave nearly destroyed the plantation. However, in 1958 Dr. Maruff started a commercial tea enterprise using the seeds and cuttings from the surviving original plantings and created the basis for the largest tea company in Australia. Its products are free of pesticides⁷.

There are now a number of other tea producers including Madura, Alpine, Two Rivers, Jemidee, Daintree and more.

How about growing your own?

There are a number of suppliers of tea plants grown from cuttings in Australia - seed-derived plants may not have the same properties as the parent. Plants can be grown in pots or as hedges since they withstand both leaf harvest and more aggressive hedge trimming. Pots have the advantage of being movable if the weather becomes too hot and dry or too cold. Soil should be enriched with compost and organic fertilizer and kept moist. It is a good idea to grow two or more plants so that you can harvest leaves from one while the other(s) keeps growing. Harvest should be possible after 2 – 4 years. For more detail click here.

As well as providing a tasty drink with a mild caffeine-hit, tea leaves can be used as a flavor enhancer in other foods and as a breath freshener.

Making the best brew

How to make the best cuppa varies with not only the type of process to make commercial products but also with water temperature, length of brewing time and whether milk is added. For advice click here and here.

Herbal Tea

If you don’t like caffeine try herbal tea! And here is the real opportunity to grow your own if you want to have really fresh leaves, reduce your environmental impacts (no transport, pesticides or packaging) and cost and to provide bee forage! However, many are also commercially available.

Most are easy to grow in pots or in the ground and the list is extremely long⁸. The most common ones are:

- Leaves: lemon balm, the mints, rosemary, raspberry, catnip, nettle, dandelion, lemon verbena, bee balm, thyme and coriander
- Flowers: elder, lavender, jasmine, chamomile.
- Roots: ginger
- Stalks: lemon grass
- Other: rose hips
- More for medicinal use: Horsetail, hyssop, motherwort, mugwort, Echinacea, yarrow, feverfew, calendula petals, fennel, sage.

Use fresh or air dry. To maintain plants, use only a few leaves at a time. Because some of these grow very easily, they are regarded as weeds. So watch out for those with invasive roots e.g. nettle, mints, raspberry, which are best grown in pots. Also be careful with those that establish too easily from seed e.g. nettle and lemon balm, which should be pruned before the flowers set seed.

Native herbal teas

Even better, try tea from Australian native plants. Perhaps the easiest to grow are lemon myrtle Backhousia citriodora or aniseed myrtle Syzgium anisata. Although they are both rain forest trees they are very adaptable and don't grow more than about 3 m in suburban settings. In summer they are covered with flowers which are attractive to bees, butterflies and nectar eating insects. Their leaves make teas tasting of lemon and aniseed respectively.

A number are commercially available e.g. lemon myrtle, wattle seed and blends incorporating peppermint gum leaves, rosella, wild hibiscus, lilli pilli, pepperberry and strawberry gum.

Tea Bags - Pros and cons

Tea quality

Making tea in a pot is not everyone’s cup of tea, so to speak. Tea bags are very convenient, they are easily transportable, allow for easy choice of strength of brew for individuals and don’t require fiddling with a tea pot.

However, the content of bags is variable. The tea is the “dust” that accumulates at the bottom of containers where tea leaves are dried. Although this dust is still tea, the fine particle size allows rapid release of flavours including unwanted bitterness so that the result may be less pleasant than tea brewed correctly from whole leaves. The content of different types of bag (rectangular, round, pyramid, sachets) may be primarily dust, whole leaves or fragments, depending on what works best with the shape⁹ and this variability means that the quality of tea flavor also varies.

Bag Composition

Unfortunately, there are potential risks associated with the material used to make some bags. They are normally made from paper or other cellulose products, such as from corn starch, but are frequently stabilised with various types of plastic e.g. rayon, PVC or polypropylene so that the paper does not fall apart in hot water¹⁰. It is likely that some of this plastic leaches out into your tea. Moreover, epichlorohydrin, a potential carcinogen, is added to the paper to increase its wet strength¹¹ and can also leach out. And even the paper may have been bleached with chlorine.

Is the Bag Compostable?

There is some debate about whether tea bags should be added to compost systems because many contain microplastics, toxins or bleach. All of these substances can be broken down by soil organisms, but it is not known to what extent they will decompose in compost. If they are not fully broken down they may leach out and find their way into ground water and eventually streams. In Europe, microplastics are found in tap water and sea salt but it is not clear if they pose a significant risk to human health¹². The contribution that tea bags make to this is pretty small though, given the large scale use of plastics elsewhere.

If you want to avoid adding these unwanted chemicals and plastics to compost, you should break tea bags open and only compost their content, throwing the outer material in the rubbish.

Our Recommendations

For a cuppa of conventional tea which is exquisite-tasting, healthy and has lower environmental impact use:

Loose leaf tea made in a tea-pot using optimum water temperature and brewing time that has been grown organically.
Use Australian grown – there is low or no pesticide contamination and environmental impacts of long distance transport are reduced.
Grow some of your own if the climate is appropriate.
If you must use tea bags, look for those that contain whole leaves and are made from wholly natural materials.
If you want to avoid caffeine go for herbal teas – either loose leaf or in bags chosen according to the criteria mentioned above.

To minimize environmental impacts buy Australian!

And even better, grow your own!

References

by SharronP

Sustainable Garden Furniture

Even if we live in an apartment, most of us have some sort of garden furniture – even if it is just one chair. Traditionally made out of wood, tables and chairs are now available in a variety of materials which differ considerably in their sustainability. Even wood is not always the most sustainable option. In considering whether garden furniture is sustainable, it is wise to consider the materials, energy inputs associated with manufacture and transportation, durability as well as social aspects of production. Most products do not undergo a whole-of-life sustainability assessment, but there is information available to help us make wiser choices.

Timber

Jarrah, teak, merbau and western red cedar are timbers used for outdoor furniture in Australia. Western red cedar furniture is not so common here as it grows in Canada and North America and its export is restricted. However, since trees are fast growing and reach heights of 70m, it is widely claimed to be a sustainable timber when grown in plantations.

Teak is a rainforest timber, sourced from Asia. While rainforests are host to 80% of the species that have been recorded, around 324 square kilometres are destroyed yearly with a similar amount degraded daily. This not only reduces habitat for dependent fauna, it also decreases the amount of vegetation which acts as a sink for carbon dioxide.

Jarrah is popular because of its resistance to rot and attractive red colour when new. It grows in the south west of Western Australia. It is an important habitat tree because of its height (up to 40 m) and trunk diameter (3m).

Merbau, also known as kwila or ipil, comes from a slow growing rainforest tree taking 75 – 80 years to mature. Because of the attractiveness of its wood, extensive and illegal harvesting has caused Merbau trees to be classified as endangered, likely to become extinct in 30 – 35 years.

Recycled timber

You might also look out for tables and chairs made either wholly or partly out of recycled timber. There seems to be an increase in manufacturers of such products.

Plastic

Due to increasing industrialization, plastic has become a cheap alternative to timber. But most of it is unsustainable because of the high material and energy inputs in its manufacture which also produces polluting waste products and its lack of durability due to degradation by sun and rain in an outdoor environment.

Recycled plastic

Over recent years, high density polyethylene (HDPE) derived from recycling plastic has offered a useful alternative for strong furniture structure. It withstands outdoor conditions, will not rot, crack or be attacked by pests, does not need sealing or maintenance, is non-toxic and can be screwed and sawn in the same way as timber. Available in a range of natural colours - although it can be painted - it has a long life. It is unlikely to be blown away since it is heavier than normal plastic furniture.

However, be sure to check the details of the nature of any such product – we have observed furniture that is made from plastic that has similar properties, but is not made from recycled material.

Stainless Steel

Much outdoor furniture is now made from stainless steel in combination with other materials. However, steel requires high energy inputs to manufacture. But it is durable - resisting corrosion - can be recycled and more than 50% is made from stainless steel scrap which has been re-melted. It is light, but strong, and is easy to maintain.

If it has a high recycled content and is in combination with glass or a sustainable or recycled timber (as a table top) it is a relatively sustainable product. However, stainless steel chairs often include plastic strapping (possibly made from dyed acrylic) for sides or seats. Table tops and seats may be made from unsustainable timber e.g. kwila or rosewood. Also take care with the use of “eco” in brand or store names – it is sometimes used inappropriately.

Aluminium

Furniture made from this metal has similar advantages and disadvantages to stainless steel. It is somewhat lighter which may be a benefit for moving furniture around, but remember that a large amount of energy is used in extracting aluminium from bauxite and subsequent smelting.

Wicker

This is the term used to describe the result of weaving various types of material to create furniture. Traditionally it was made from different species of grass ranging from bamboo, cane or rattan to sea grass. Sometimes a combination is used with bamboo constituting the supporting frame and woven, finer material comprising seats and backs of chairs. The resulting furniture is stylish and natural-looking.

The species of grass used generally grow rapidly, so harvesting is usually sustainable. However, although this furniture withstands exposure to weather it is not as long lasting as stainless steel and, therefore, is usually used under some sort of cover.

Some wicker furniture uses woven vinyl or plastic which involve high energy manufacturing inputs and also creates chemical wastes that need care in disposal. So just because it is called “wicker” does not make it sustainable.

Soft materials for seats or cushions

Many types of outdoor furniture use flexible material for slung seats or backs of chairs or to cover cushions. Much of this material is plastic of some sort:

Vinyl (PVC), polyester fabric coated with PVC or dyed acrylic which sometimes incorporates cotton. Vinyl gets very hot to sit on and cannot be recycled. The others vary in durability.

The most sustainable fabric is probably canvas made from cotton or linen (it used to be hemp). It is a natural material, very durable and cheap. However, remember that cotton, unless organic, has been grown with an amazing number of pesticides which pollute are and waterways. However, production of fabric and dying it usually removes residual pesticide.

Longevity vs Manufacturing Inputs vs Cost

It can be tricky to weigh up durability, the environmental impacts of component materials and the cost. In general, long-lasting, low environmental impact materials tend to require a higher initial outlay. However, if they are durable, requiring little maintenance, then that cost is worthwhile. Their capacity to be recycled at the end of their lifetime is also worth taking into account.

by SharronP

Sustainable Garden Edging

Why bother with garden edging? Why not just let plants grow up to the edges of lawn (if you have it) or of paths? Unfortunately, soil and mulch migrate from garden beds because of rain or birds which love to scratch in it. And some plants send their roots further than the bed and, conversely, some lawn grasses will enter your garden beds. Some sort of edging is necessary if you want raised beds.

There are many forms of edging commercially available, but they differ significantly in their sustainability. However, natural or recycled materials make excellent edging and can add uniqueness to your garden as well as minimising manufacturing impacts and waste going to landfill. Read more

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