Apr 272017
 

Every garden is sometimes afflicted with pests – grasshoppers, cabbage white butterfly caterpillars, scale and aphids being very common.  Is it always necessary to use a spray, either bought or home-made?  Just having certain plants in your garden can help repel insects or confuse them with their strong scent.  If they are planted near susceptible plants they will contribute to keeping insects at bay. Here are some suggestions, mostly  taken from the book Pest-Repellent Plants, by Penny Woodward (published by Hyland House). You can find loads more wonderful information at Penny’s website at www.pennywoodward.com.au.

Marjoram and oregano

These two will deter pumpkin beetles when planted near cucurbits. They also confuse white cabbage butterflies when planted near brassicas. A hedge growing around an onion patch will protect the onions from onion maggot.

Marigolds

Planted randomly through a garden, marigold smell tends to confuse flying insects! Grow them amongst crops such as tomato to repel whitefly and soil nematodes, with carrots to deter carrot fly and with brassicas to mask their smell. Between rows of beans, marigolds will deter spider mites and a range of beetles.

Lavender

Strongly scented lavenders will protect nearby plants from insects such as whitefly, and lavender planted under and near fruit trees can deter codling moth. A hedge around onions will protect them from onion maggot, and lavenders planted near native plants can repel the moths that produce borer larvae.

Remember though, that there is a weed species of lavender and this must be avoided. Lavandula stoechas (Topped Lavender or French Lavender) and its 40 odd cultivars is still allowed into Australia but it is subject to legislation in Victoria as a regionally prohibited and regionally controlled weed, proclaimed in the Victorian Government Gazette of 18 December 1997 (www.dpi.vic.gov.au). It is also a problem in many other areas, especially South Australia.

Garlic

Garlic has the ability to repel airborne and soilborne pests. It deters beetles, spider mites and fruit flies. The smell of garlic and other alliums confuses carrot fly and white cabbage butterfly. When planted amongst raspberry canes garlic will protect them from a variety of grubs.

Basil

The general insect repellent properties of basil make it an excellent plant to grow throughout the vegetable garden. Basil especially protects cabbages, beans, and tomatoes. It even protects cucurbits from downy mildew. Grow basil in pots near doorways to deter flies.

Sage

Sage attracts bees but repels many pest insects and protects onions from onion maggot. Sage also repels ants, so grow it in pots near doorways, and lay sprigs of sage on shelves and entry points. It is also supposed to keep mice away.

Rosemary

Its scent masks the smell of other plants such as brassicas and deters carrot fly. A hedge of rosemary around a vegetable garden acts as a general pest repellent for insects such as whitefly. Add sprigs of rosemary to clothes cupboards to repel moths and silverfish.

Land cress Barbarea vulgaris

This plant is also known as Bittercress, Herb Barbara, Rocketcress, Yellow Rocketcress, Winter Rocket, and Wound Rocket.  It should not be confused with Barbarea verna, a different species, but which has similar properties.  It is very attractive to cabbage white butterflies which lay their eggs on it.  The larvae which hatch out and feed on the leaves, which have a high saponin content, die.  So when planted in your garden, maybe even amongst your cabbages and kale, it will minimise attack on these vegetables by these nasty caterpillars.

It is edible chopped in salads, but make sure you use the young leaves since bitterness increases as the plants mature.  It is best not to let the pretty yellow flowers go to seed unless you want a prolific crop of new plants.

Pics © Elaine Shallue and Sharron Pfueller (SGA)

  13 Responses to “Pest Repellent Plants”

  1. I’ve been using a 50-50 mix of 3% hydrogen peroxide and water to control bugs in my veggie garden here in central Florida this year and had a good deal of success… not sure it kills the bugs but it sure seems to run them off. :–). It degrades into Oxygen and water and doesn’t appear to harm any of the plants I’ve used it on. I’ve tried neem before and been disappointed, both with the results (not very effective) and it’s adverse affect on some plants.

    • Hydrogen peroxide is a suitable alternative for some pests. But just watch out that it doesn’t get on the soil, it can harm soilmicrobial life which is important in maintaining soil fertility.

  2. The story is good and very informative.

    I would like to add – Take 20 ml Dettol Liquid Soap + 1 ml Neem oil + 1 ml Garlic Oil and mix these thoroughly in 1 liter of water.

    Fill this into a sprayer and spray it on the effected plants.

    Follow after 7 days.

    This is good for Aphids, caterpillars, sucking pests etc.

  3. Great article. Made me check out Penny Woodward site and I have purchased the book, it looks very interesting.
    Thanks

  4. Attempt #3; An address error on nos 1 and 2. I’m sorry.
    Can you suggest a means of controlling black aphids that have taken over our Society Garlic. We have tried several natural methods with no success. Regards RG.

    • I have heard of people successfully using one tablespoon of natural soap flakes (like Lux) in four litres of warm water. Only spray affected plants as this spray is not selective. White oil can be used at the rate of 20 ml to 1 litre of water. Do not spray at temperatures over 30 degrees. Both of these sprays work by suffocating the aphids.

  5. Can you suggest a means of controlling black aphids on Society Garlic. We have tried a few natural remedies with no success. Regards RG

    • I have heard of people successfully using one tablespoon of natural soap flakes (like Lux) in four litres of warm water. Only spray affected plants as this spray is not selective. White oil can be used at the rate of 20 ml to 1 litre of water. Do not spray with temperatures over 30 degrees. Both of these sprays work by suffocating the aphids.

  6. Thanks for this article. I have also planted catmint around my veggie plot to attract bees. Is this a good idea?

  7. How can one repel harlequin bugs? I no longer have hollyhocks and I miss them in summer.

 Leave a Reply

(required)

(required)

*

Show Buttons
Hide Buttons