Plants

Deterring pests
There are many ways we can use plants in the garden to aid in our quest to produce the best vegetables we could possibly eat. By making use of their beneficial qualities, we can improve the soil and plants around them, and hopefully reduce the need for insecticides.

Insectary plants are those plants that have some important interaction with insects, whether it is to attract beneficial insects or to repel pests.

Insectary plants to repel pest insects

Highly aromatic herbs will help to deter pest insects, but it is best not to plant them too close to your veggies as many are large perennials or form a dense mat that can compete with crop plants. We mostly use them as perimeter crops or place them in pots around the patch.

* Asterisk denotes plants that have both attractant and repellent qualities

Allium (onion family)

Aphids (plant amongst crops that are aphid prone)

*Amaranthus

Cutworm

Basil

Aphids / Whitefly / House fly / Mosquitoes / Carrot fly / Asparagus beetle / Fruit fly (especially on tomatoes)

Borage

Tomato worm / Cabbage worm / Wasps / Gives nearby plants increased resistance to pests

Catnip

Ants / Flea beetle / Aphid / Weevil / Cockroaches / Potato beetle / Squash bug

Celery

Cabbage white butterfly
(plant near cauliflower and cabbage)

*Chamomile

Flying insects

Chervil

Several insect pests

Chives

Carrot fly / Aphid / Japanese beetle

Chrysanthemums

Cockroaches / Ants / Ticks / Fleas / Lice / Silverfish / Root nematodes
Chrysanthemum cinerariaefolium is the source of pyrethrum. It will inhibit the development of root knot nematodes.

Citronella grass

Insects / Cats

*Clover

Aphids / Wire worm

*Coriander

Aphids / Potato beetle / Spider mite

*Cosmos

Corn earworm

Costmary (chrysanthemum)

Insect repellent when strewn around plants

Comfrey

Few pests will harm it

Dahlia

Root nematodes

*Daisy family (Compositae)

The daisy family includes Mugwort, Sagebrush, Wormwood, Tarragon, Southern wood.

Whitefly / Cabbage white butterfly / Ants / Cabbage caterpillar / Carrot fly / Moths / Beetles / Mice

*Dill

Lures pests away from other crops- White cabbage moth / Aphids / Spider mite / Squash bug

Dog bane

- repels a range of pests and will protect nearby plants from attack
- grow in pots and move around to areas that need protecting
- has a very strong smell, and is said to deter dogs as well

*Fennel

Strong aroma and flavour deters many insects, particularly aphids

*Feverfew

Dried leaves deter moths

Garlic

Codling moth / Snails / Carrot fly / Aphids (particularly from rose bushes)

Horseradish

- contains a mustard type oil which repels insects especially potato bug and beetles
- a tea made from the root is also effective as an anti-bacterial and anti-fungal spray
- can be invasive

Hyssop

Cabbage white butterfly (aroma confuses them)

Lad’s love

Ants / White cabbage moth / Fruit fly / Mosquitoes / Other insects

Lemon grass

Flying insects

Lemon verbena

Midges / Mosquitoes

*Marigold dwarf, daisy family

- inhibits attacks by pests and diseases
- repels many pests including white fly that attacks tomatoes
- deters eelworm (nematodes) in soil; roots excrete chemicals that kill nematodes in the soil (good for all root vegetables)
- deters some beetles that pupate in the soil
- foliage deters insects, especially white fly from tomatoes
- if planted within the veggie patch it may weaken the plants nearby; best to use it as a manure crop in between plantings and as a perimeter border
- Mexican marigold is the most powerful of insect repelling plants

Marjoram

Pumpkin beetle / confuses Cabbage white butterfly if planted nearby (try in pots)

Mint

Aphids / Flea beetle / Cabbage moth / Flies / Caterpillars / Mice / Ants (mixed with parsley, dried or fresh)

*Mugwort

Onion fly / Carrot fly (lay branches amongst rows)

*Nasturtium

Aphids / White fly / Cucumber beetle / other chewing pests /
- decoy for brassicas

Nettles

A mild insecticide

*Oregano

- Cucumber beetle / Cabbage butterfly / Pumpkin beetle / Cabbage white butterfly (confuses it if planted nearby)
- can be strewn around with parsley to keep pests away

*Parsley

Aphids / Carrot root fly

Peppermint

Rodents

Plecanthrus (tropical coleus)

Ants / Insects

Pyrethrum (Chrysanthemum cinerariaefolium)

- dried leaves, powdered and sprinkled (will kill good insects as well)
- spray available commercially
- pretty plant- good near strawberries to keep pests away

*Rosemary

- Carrot fly / Cabbage and house moths / Mosquitoes / Bean beetle / Slugs and snails /
- Useful strewing herb to repel flies and fleas
- can be rubbed into the coat of pets

Rue

- Cucumber beetle / Flea beetle / Flies / Fleas (rub a tea into coats of pets)
- Dried leaves are a powerful antibacterial and insecticide (insects and slugs hate it)

*SAGE

- White cabbage moth
- protects carrots and cabbage from fly and moth
- sprinkle dried sage around for mildew

Santolina

- Moths / other flying insects

Savory (summer and winter)

- Bean beetle

Spearmint

- Cabbage caterpillar / Flea / Moths / Ants / Beetles / Squash bug / Mice

*Tansy

- Ants / Beetles / Fleas / Squash bug / Cut worms / Cabbage white butterfly / Mosquitoes / Moths / Flying pests / strong insect repellent (rub in pets coats for fleas)

Tomato

- Asparagus beetle

*Thyme

- Cabbage root fly / Corn earworm / Whitefly

Savory (summer and winter)

Bean beetle

Woodruff

- many insects

Wormwood

- Onion and carrot fly (lay branches out in their rows) / Cabbage butterflies / Moths
- hedge around chicken coups to protect against lice
- make a weak infusion to use as an insecticide on older plants
- rub on pet coats for fleas