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 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 large growing perennials or ones that form a dense mat too close to your veggies as they can compete with crop plants. We mostly use them as perimeter crops or place them in pots around the patch. Some are crop plants eg. Onions or annual herbs, so these can be planted amongst other vegetables.
* Asterisk denotes plants that have both attractant and repellent qualities
* 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)
(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.
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
Comfrey
Few pests will harm it
Dahlia
Root nematodes
*Daisy family (Compositae)
Includes mugwort, sagebrush, wormwood, tarragon, southernwood
Whitefly / Cabbage white butterfly / Ants / Cabbage caterpillar / Carrot fly / Moths / Beetles / Mice
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
Rrepels 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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)
- 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
- 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
- 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
