The Mysteries of
Companion Planting
Companion planting is based on the idea that certain
plants can benefit others when planted in nearby. The scientific and
traditional basis for these plant associations are discussed. A
companion planting chart for common herbs, vegetables, and flowers is
provided, as is a listing of literature resources for traditional
companion planting.
Companion Planting is
what you do yourself so that you don't have to use chemicals in your
garden.
Generally, companion planting is thought of as a small-scale gardening
practice. However, the term here is applied in its broadest sense to
include applications to commercial horticultural and agronomic crops.
Here are some basic principles:
Trap
Cropping
Sometimes, a neighboring crop may be selected because it is more
attractive to pests and serves to distract them from the main crop. An
excellent example of this is the use of collards to draw the diamond
back moth away from cabbage
Symbiotic Nitrogen Fixation
Legumes—such as peas, beans, and clover—have the ability to fix
atmospheric nitrogen for their own use and for the benefit of
neighboring plants via symbiotic relationship with Rhizobium bacteria.
Forage legumes, for example, are commonly seeded with grasses to
reduce the need for nitrogen fertilizer. Likewise, beans are sometimes
interplanted with corn.
Biochemical Pest Suppression
Some
plants exude chemicals from roots or aerial parts that suppress or
repel pests and protect neighboring plants. The African marigold, for
example, releases thiopene—a nematode repellent—making it a good
companion for a number of garden crops. The manufacture and release of
certain biochemicals is also a factor in plant antagonism.
Allelochemicals such as juglone—found in black walnut—suppress the
growth of a wide range of other plants, which often creates a problem
in home horticulture. A positive use of plant allelopathy is the use
of mow-killed grain rye as a mulch. The allelochemicals that leach
from rye residue prevent weed germination but do not harm transplanted
tomatoes, broccoli, or many other vegetables.
Physical Spatial Interactions
For
example, tall-growing, sun-loving plants may share space with
lower-growing, shade-tolerant species, resulting in higher total
yields from the land. Spatial interaction can also yield pest control
benefits. The diverse canopy resulting when corn is companion-planted
with squash or pumpkins is believed to disorient the adult squash vine
borer and protect the vining crop from this damaging pest. In turn,
the presence of the prickly vines is said to discourage raccoons from
ravaging the sweet corn.
Nurse
Cropping
Tall
or dense-canopied plants may protect more vulnerable species through
shading or by providing a windbreak. Nurse crops such as oats have
long been used to help establish alfalfa and other forages by
supplanting the more competitive weeds that would otherwise grow in
their place. In many instances, nurse cropping is simply another form
of physical-spatial interaction.
Beneficial Habitats
Beneficial habitats—sometimes called refugia—are another type of
companion plant interaction that has drawn considerable attention in
recent years. The benefit is derived when companion plants provide a
desirable environment for beneficial insects and other
arthropods—especially those predatory and parasitic species which help
to keep pest populations in check. Predators include ladybird beetles,
lacewings, hover flies, mantids, robber flies, and non-insects such as
spiders and predatory mites. Parasites include a wide range of fly and
wasp species including tachinid flies, and Trichogramma and
ichneumonid wasps. Agroecologists believe that by developing systems
to include habitats that draw and sustain beneficial insects, the twin
objectives of reducing both pest damage and pesticide use can be
attained. For detailed information on establishing beneficial
habitats, request the ATTRA publication
Farmscaping to Enhance Biological Control.
Security Through Diversity
A more
general mixing of various crops and varieties provides a degree of
security to the grower. If pests or adverse conditions reduce or
destroy a single crop or cultivar, others remain to produce some level
of yield. Furthermore, the simple mixing of cultivars, as demonstrated
with broccoli in University of
California
research, can reduce aphid infestation in a crop.
PLANT
GUIDE
ALFALFA:
Perennial that roots
deeply. Fixes the soil with nitrogen, accumulates iron, magnesium,
phosphorous and potassium. Withstands droughts with it's long taproot
and can improve just about any soil! Alfalfa has the ability to break
up hard clay soil and can even send its' roots through rocks! Now that
is a tenacious plant! Alfalfa is practically pest and disease free. It
needs only natural rainfall to survive.
AMARANTH:
A tropical annual that
needs hot conditions to flourish. Good with sweet corn, it's leaves
provide shade giving the corm a rich, moist root run. Host to
predatory ground beetles. Eat the young leaves in salads.
ANISE:
Licorice flavored
herb, good host for predatory wasps which prey on aphids and it is
also said to repel aphids. Deters pests from brassicas by camouflaging
their odor. Improves the vigor of any plants growing near it. Used in
ointments to protect against bug stings and bites. Good to plant with
coriander.
ASPARAGUS:
Plant with Tomato, Parsley, Basil . Sprinkle parsley leaves onto the
asparagus while it is growing.
ARTEMISIAS:
See Wormwood
BASIL:
Plant with tomatoes to
improve growth and flavor. Pepper, Marigold .Basil can be helpful in
repelling thrips. It is said to repel flies and mosquitoes.
Incompatible with or near rue.
BAY
LEAF:
A fresh leaf bay leaf
in each storage container of beans or grains will deter weevils and
moths. Sprinkle dried leaves with other deterrent herbs in garden as
natural insecticide dust. A good combo: Bay leaves, cayenne pepper,
tansy and peppermint.
·
For ladybug
invasions try spreading bay leaves around in your house anywhere they
are getting in and they should leave.
BEANS:
All beans enrich the
soil with nitrogen fixed form the air. In general they are good
company for carrots, celery, chards, corn, eggplant, peas, potatoes,
brassicas, beets, radish, strawberry and cucumbers. Great for heavy
nitrogen users like corn and grain plants. French Haricot beans, sweet
corn and melons are a good combo. Summer savory deters bean beetles
and improves growth and flavor.
Incompatible with: alliums.
BUSH
BEANS:
Irish Potato,
Cucumber, Corn, Strawberry, Celery, Summer Savory -
Not compatible with Onions
POLE
BEANS:
Corn, Summer Savory,
Radish - Not
compatible with Onions, radish, sunflower, Beets, Kohlrabi,
BEE
BALM (Oswego, Monarda):
Plant with tomatoes to
improve growth and flavor. Great for attracting beneficials and bees
of course. Pretty perennial that tends to get powdery mildew.
BEET:
Good for adding
minerals to the soil. The leaves are composed of 25% magnesium making
them a valuable addition to the compost pile if you don't care to eat
them. Companions are lettuce, kohlrabi, onions and brassicas. Garlic
improves growth and flavor. They are also beneficial to beans with the
exception of runner beans.
Runner or pole beans and beets stunt each other's
growth.
BORAGE:
Companion plant for
tomatoes, squash, strawberries and most plants. Deters tomato
hornworms and cabbage worms. One of the best bee and wasp attracting
plants. Adds trace minerals to the soil and a good addition the
compost pile. The leaves contain vitamin C and are rich in calcium,
potassium and mineral salts. Borage may benefit any plant it is
growing next to via increasing resistance to pests and disease. It
also makes a nice mulch for most plants. Borage and strawberries help
each other and strawberry farmers always set a few plants in their
beds to enhance the fruits flavor and yield. Plant near tomatoes to
improve growth and disease resistance. After you have planned this
annual once it will self seed. Borage flowers are edible.
BRASSICA:
Benefit from
chamomile, peppermint, dill, sage, and rosemary. They need rich soil
with plenty of lime to flourish.
BUCKWHEAT:
Accumulates calcium and can be grown as an excellent cover crop.
Attracts hoverflies in
droves. (Member of the brassica family.)
CABBAGE:
Celery, dill, onions
and potatoes are good companion plants. Aromatic Herbs, Beets, Onion
Family, Chamomile, Spinach, Chard -
Incompatible with: dill,
strawberries, tomatoes and pole beans.
CARAWAY:
Good for loosening
compacted soil with it's deep roots so it's also compatible next to
shallow rooted crops. Tricky to establish. The flowers attract a
number of beneficial insects especially the tiny parasitic wasps.
Incompatible with: dill
and fennel.
CARROTS:
Their pals are leaf
lettuce, radish, onions and tomatoes. English Pea, Rosemary, Sage,
Incompatible with: dill
CATNIP:
Deters flea beetles,
aphids, Japanese beetles, squash bugs, ants and weevils. We have found
it repels mice quite well: mice were wreaking havoc in our
outbuildings, we spread sprigs of mint throughout and the mice split!
Use sprigs of mint anywhere in the house you want deter mice and ants.
Smells good and very safe.
CELERY:
Companions: cabbage
family, tomato., Onion, Bush Beans, Nasturtium
CHAMOMILE, GERMAN:
Annual. Improves
flavor of cabbages, cucumbers and onions. Host to hoverflies and
wasps. Accumulates calcium, potassium and sulfur, later returning them
to the soil. Increases oil production from herbs. Leave some flowers
unpicked and German chamomile will reseed itself. Roman chamomile is
a low growing perennial that will tolerate almost any soil conditions.
Both like full sun. Growing chamomile of any type is considered a
tonic for anything you grow in the garden.
CHARDS:
Companions: Bean,
cabbage family and onion.
CHERVIL:
Companion to radishes
for improved growth and flavor. Keeps aphids off lettuce. Said to
deter slugs. Likes shade.
CHIVES:
Improves growth and
flavor of carrots and tomatoes. Keeps aphids help to keep aphids away
from tomatoes, mums and sunflowers. Chives may drive away Japanese
beetles and carrot rust fly. Planted among apple trees it helps
prevent scab and among roses it prevents black spot. You will need
patience as it takes about 3 years for plantings of chives to prevent
the 2 diseases. A tea of chives may be used on cucumbers and
gooseberries to prevent downy and powdery mildews.
See chive tea on disease page.
CHRYSANTHEMUMS:
C. coccineum kills
root nematodes. (the bad ones) It's flowers along with those of C.
cineraruaefolium have been used as botanical pesticides for centuries.
(i.e. pyrethrum) White flowering chrysanthemums repel Japanese
beetles.
CLOVER:
Long used as a green
manure and plant companion. Attracts many beneficials. Useful planted
around apple trees to attract predators of the woolly aphid.
COMFREY:
Accumulates calcium,
phosphorous and potassium. Likes wet spots to grow in. Traditional
medicinal plant. Good trap crop for slugs.
More on comfrey.
CORIANDER:
Repels aphids, spider
mites and potato beetle. A tea from this can be used as a spray for
spider mites. A partner for anise.
CORN:
Irish Potato, Beans, English Pea, Pumpkin, Cucumber,
Squash Not compatible
with tomato
COSTMARY:
This 2-3 foot tall
perennial of the chrysanthemum family helps to repel moths.
CUCUMBERS:
Cucumbers are great to
plant with corn and beans. The three plants like the same conditions
warmth, rich soil and plenty of moisture. Let the cucumbers grow up
and over your corn plants. A great duet is to plant cukes with
sunflowers. The sunflowers provide a strong support for the vines.
Cukes also do well with peas, beets and carrots. Dill planted with
cucumbers by attracting beneficial predators. Nasturtium improves
growth and flavor.
Incompatible with: sage, Irish Potato, Aromatic Herbs
DAHLIAS:
These beautiful,
tuberous annuals that can have up to dinner plate size flowers repels
nematodes!
DILL:
Improves growth and
health of cabbage. Do not plant near carrots or caraway. Best friend
for lettuce. Attracts hoverflies and predatory wasps. Repels aphids
and spider mites to some degree. Also may repel the dreaded squash
bug! (scatter some good size dill leaves on plants that are suspect to
squash bugs, like squash plants, yeah that's the ticket.) Dill goes
well with onions, cabbage, sweet corn and cucumbers. Dill does attract
the tomato horn worm so it would be useful to plant it somewhere away
from your tomato plants to keep the destructive horn worm away from
them. We like to plant it for the swallowtail butterfly caterpillars
to feed on. Even their caterpillars are beautiful.
EGGPLANT:
Beans, Marigold
ELDERBERRY:
A spray (see
insect treatments) made from the leaves can be used against
aphids, carrot root fly, cuke beetles and peach tree borers. Put
branches and leaves in mole runs to banish them. Yes, it works!
FLAX:
Plant with carrots,
and potatoes. Flax contains tannin and linseed oils which may offend
the Colorado potato bug. Flax is an annual from 1-4 feet tall with
blue or white flowers that readily self sows.
FOUR-O'CLOCKS:
Draw Japanese beetles
like a magnet which then dine on the foliage. The foliage is pure
poison to them and they won't live to have dessert! It is important to
mention that Four O'clock are also poisonous to humans. Please be
careful where you plant them if you have children. They are a
beautiful annual plant growing from 2-3 feet high with a bushy growth
form.
GARLIC:
Plant near roses to
repel aphids. Accumulates sulfur: a naturally occurring fungicide
which will help in the garden with disease prevention. Garlic is
systemic in action as it is taken up the plants through their pores
and when used as a soil drench is also taken up by the roots. Has
value in offending codling moths, Japanese beetles, root maggots,
snails, and carrot root fly. Researchers have observed that
time-released garlic capsules planted at the bases of fruit trees
actually kept deer away! Hey, worth a try! Concentrated garlic sprays
have been observed to repel and kill whiteflies, aphids and fungus
gnats among others with as little as a 6-8% concentration! It is safe
for use on orchids too.
·
Try concentrated
Garlic Barrier Insect Repellent!
Geranium:
Repels cabbage worms
and Japanese beetles, plant around grapes, roses, corn, and cabbage.
GOPHER
PURGE:
Deters gophers, and
moles.
GRAPES:
Hyssop is beneficial
to grapes as are beans, peas, or blackberries. Keep radishes and
cabbage away from grapes. Planting clover increases the soil fertility
for grapes. Chives with grapes help repel aphids. Plant your vines
under Elm or Mulberry trees!
HORSERADISH:
Plant in containers in
the potato patch to keep away Colorado potato bugs. There are some
very effective insect sprays that can be made with the root. Use the
bottomless pot method to keep horseradish contained. Also repels
Blister beetles. We have observed that the root can yield anti-fungal
properties when a tea is made from it. (See:
Horseradish: Disease)
HOREHOUND: (Marrubium Vulgare)
like many varieties in
the mint family, the many tiny flowers attract Braconid and Icheumonid
wasps, and Tachnid and Syrid flies. The larval forms of these insects
parasitize or otherwise consume many other insects pests. It grows
where many others fail to thrive and can survive harsh winters. Blooms
over a long season, attracting beneficial insects almost as long as
you are likely to need them. For best results use horehound directly
as a companion plant. Stimulates and aids fruiting in tomatoes and
peppers.
HYSSOP:
Companion plant to
cabbage and grapes, deters cabbage moths and flea beetles. Do not
plant near radishes. Hyssop may be the number one preference among
bees and some beekeepers rub the hive with it to encourage the bees to
keep to their home. It is not as invasive as other members of the mint
family making it safer for interplanting.
KELP:
When used in a powder
mixture or tea as a spray, this versatile sea herb will not only repel
insects but feed the vegetables. In particular we have observed that
kelp foliar sprays keep aphids and Japanese beetles away when used as
a spray every 8 days before and during infestation times. If you have
access to seaweed, use it as a mulch to keep slugs away.
LAMIUM:
This will repel potato
bugs- a big problem for many gardeners!
LARKSPUR:
An annual member of
the Delphinium family, larkspur will attract Japanese beetles. They
dine and die! Larkspur is poisonous to humans too!
LAVENDER:
Repels fleas and
moths. Prolific flowering lavender nourishes many nectar feeding and
beneficial insects. Use dried sprigs of lavender to repel moths. Start
plants in winter from cuttings, setting out in spring.
LEEKS:
Use leeks near
carrots, celery and onions which will improve their growth. Leeks also
repel carrot flies.
LEMON
BALM:
Sprinkle throughout
the garden in an herbal powder mixture to deter many bugs. Lemon balm
has citronella compounds that make this work: crush and rub the leaves
on your skin to keep mosquitoes away! Use to ward off squash bugs!
LETTUCE:
Carrot, Radish,
Strawberry, Cucumber
LOVAGE:
Improves flavor and health of most plants. Good habitat for ground
beetles. A large plant, use one planted as a backdrop. Similar to
celery in flavor.
MARIGOLDS:
(Calendula):
Given a lot of credit
as a pest deterrent. Keeps soil free of bad nematodes; supposed to
discourage many insects. Plant freely throughout the garden. The
marigolds you choose must be a scented variety for them to work. One
down side is that marigolds do attract spider mites and slugs.
Note
that within one night after planting marigold plants, all the leaves
were already eaten off, though the flowers were still on. Blamed it
on geckos, but probably is slugs or snails. yuck. Slugs and snails
love marigolds.
·
French Marigold (T. patula)
has roots
that exude a substance which spreads in their immediate vicinity
killing nematodes. For nematode control you want to plant dense areas
of them. There have been some studies done that proved this nematode
killing effect lasted for several years after the plants were These
marigolds also help to deter whiteflies when planted around tomatoes
and can be used in greenhouses for the same purpose. Whiteflies hate
the smell of marigolds.
·
Mexican marigold (T. minuta)
is the most
powerful of the insect repelling marigolds and may also overwhelm weed
roots such as bind weed! It is said to repel the Mexican bean beetle
and wild bunnies! Be careful it can have an herbicidal effect on some
plants like beans and cabbage.
MARJORAM:
As a companion plant
it improves the flavor of vegetables and herbs. Sweet marjoram is the
most commonly grown type.
MELONS: Companions:
Corn, pumpkin, radish
and squash. Other suggested helpers for melons are as follows:
Marigold deters beetles, nasturtium deters bugs and beetles. Oregano
provides general pest protection.
MINT:
Deters white cabbage moths, ants, rodents, flea beetles, fleas, aphids
and improves the health of cabbage and tomatoes. Use cuttings as a
mulch around members of the brassica family. It attracts hoverflies
and predatory wasps. Earthworms are quite attracted to mint plantings.
Be careful where you plant it as mint is an incredibly invasive
perennial. Placing mint (fresh or dried) where mice are a problem is
very effective in driving them off!
MOLE
PLANTS: (castor bean plant)
Deter moles and mice
if planted here and there throughout the garden. Drop a seed of this
in mole runs to drive them away. This is a poisonous plant.
See Moles: Critter Trouble
MORNING GLORIES:
They attract
hoverflies. Plus if you want a fast growing annual vine to cover
something up morning glory is an excellent choice.
NASTURTIUMS:
Plant as a barrier
around tomatoes, radishes, cabbage, cucumbers, and under fruit trees.
Deters wooly aphids, whiteflies, squash bug, cucumber beetles and
other pests of the cucurbit family. Great trap crop for aphids (in
particular the black aphids) which it does attract, especially the
yellow flowering varieties. Likes poor soil with low moisture and no
fertilizer. It has been the practice of some fruit growers that
planting nasturtiums every year in the root zone of fruit trees allow
the trees to take up the pungent odor of the plants and repel bugs. It
has no taste effect on the fruit. A nice variety to grow is Alaska
which has attractive green and white variegated leaves. The leaves,
flowers and seeds are all edible and wonderful in salads!
Try our recipe for: Nasturtium Salad
NETTLES, STINGING:
The flowers attract
bees. Sprays made from these are rich in silica and calcium.
Invigorating for plants and improves their disease resistance. Leaving
the mixture to rot, it then makes an excellent liquid feed. Comfrey
improves the liquid feed even more.
Hairs on the nettles' leaves contain formic acid which
"stings" you.
ONIONS:
Planting chamomile
with onions improves their flavor. Other companions are savory,
carrot, leek, beets, kohlrabi, strawberries, brassicas, dill, lettuce
and tomatoes. Intercropping onions and leeks with your carrots
confuses the carrot and onion flies! Beets, Carrot, Lettuce, Cabbage
Family, Onions planted with strawberries help the berries fight
disease. Incompatible
with: Beans, English Peas and summer savory.
OPAL BASIL:
An annual herb that is
pretty, tasty and said to repel hornworms!
OREGANO:
Can be used with most
crops but especially good for cabbage. Plant near broccoli, cabbage
and cauliflower to repel cabbage butterfly and near cucumbers to repel
cucumber beetle. Also benefits grapes.
PARSLEY:
Plant among and
sprinkle the leaves on tomatoes, and asparagus. Use as a tea to ward
off asparagus beetles. Attracts hoverflies. Let some go to seed to
attract the tiny parasitic wasps and hoverflies. Parsley increases the
fragrance of roses when planted around their base. Rose problems?
See: Rose Rx for answers.
PEAS:
Peas fix nitrogen in
the soil. Plant next to corn and they will provide extra nitrogen.
Corn is a heavy feeder so this is a great combination! Companions for
peas are bush beans, Pole Beans, Carrots, Celery, Chicory, Corn,
Cucumber, Eggplant, Parsley, Early Potato, Radish, Spinach,
Strawberry, Sweet pepper and Turnips.
Incompatible with: onions, Gladiolus, Irish Potato.
PEPPERMINT:
Repels white cabbage
moths, aphids and flea beetles. It is the menthol content in mints
that acts as an insect repellant. Bees and other good guys love it.
PEPPERS, BELL (Sweet Peppers):
Plant peppers near
tomatoes, parsley, basil, and carrots.
Onions make an excellent companion plant for peppers.
They do quite well with okra as it shelters them and protects the
brittle stems from wind. Don't plant them near fennel or kohlrabi.
They should also not be grown near apricot trees because a fungus that
the pepper is prone to can cause a lot of harm to the apricot tree.
Peppers can double as ornamentals, so tuck some into flowerbeds and
borders. Harvesting tip: The traditional bell pepper, for example, is
harvested green, even though most varieties will mature red, orange,
or yellow. Peppers can be harvested at any stage of growth, but their
flavor doesn't fully develop until maturity.
PEPPERS, HOT:
Chili peppers have
root exudates that prevent root rot and other Fusarium diseases. Plant
anywhere you have these problems. Teas made from hot peppers can be
useful as insect sprays. Hot peppers like to be grouped with
cucumbers, eggplant, escarole, tomato, okra, Swiss chard and squash.
Herbs to plant near them include: basils, oregano, parsley and
rosemary
PENNYROYAL:
Repels fleas. The
leaves when crushed and rubbed onto your skin will repel chiggers,
flies, gnats, mosquitoes and ticks.
Warning: Pennyroyal is highly toxic to cats. It should
not be planted where cats might ingest it and never rubbed onto their
skin.
PETUNIAS:
They repel the
asparagus beetle, leafhoppers, certain aphids, tomato worms, Mexican
bean beetles and general garden pests. A good companion to tomatoes,
but plant everywhere. The leaves can be used in a tea to make a potent
bug spray.
POACHED EGG PLANT:
Grow poached egg plant
with tomatoes, they will attract hover flies and hover flies eat
aphids.
POTATO:
Companions for
potatoes are bush bean, members of the cabbage family, carrot, celery,
corn, dead nettle, flax, horseradish, marigold, peas, petunia, onion
and Tagetes marigold. Protect them from scab by putting comfrey leaves
in with your potato sets at planting time. Horseradish, planted at the
corners of the potato patch, provides general protection.
Don't plant these around
potatoes: cucumber, kohlrabi, parsnip, pumpkin, rutabaga, squash
family, sunflower, turnip and fennel. Keep potatoes and tomatoes apart
as they both can get early and late blight contaminating each other.
POTATO- IRISH:
Beans, Corn, Cabbage Family, Marigolds, Horseradish
Incompatible with:
Pumpkin, Squash, Tomato,
Cucumber, Sunflower
PUMPKINS:
Pumpkin pals are corn,
melon and squash. Marigold deters beetles. Nasturtium deters bugs,
beetles. Oregano provides general pest protection.
Incompatible with: Irish
Potato
PURSLANE:
This edible weed makes
good ground cover in the corn patch. Use the stems, leaves and seeds
in stir-frys. Pickle the green seed pod for caper substitutes. If
purslane is growing in your garden it means you have healthy, fertile
soil!
RADISH:
Companions for
radishes are: radish beet, bush beans, pole beans, carrots, chervil,
cucumber, lettuce, melons, nasturtium, parsnip, peas, spinach and
members of the squash family. Why plant radishes with your squash
plants? Radishes may protect them from squash borers! Anything that
will help keep them away is worth a try. Chervil and nasturtium
improve growth and flavor. Planting them around corn and letting them
go to seed will also help fight corn borers. Chinese Daikon and Snow
Belle are favorites of flea beetles. Plant these at 6 to 12 inch
intervals broccoli. In one trial, this measurably reduced damage to
broccoli. Incompatible
with: hyssop plants,
cabbage, cauliflower, brussel
sprouts and turnips. Planting an early
row of radishes may lure flea beetles away from susceptible plants.
ROSEMARY:
Companion plant to cabbage, beans, carrots and sage. Deters cabbage
moths, bean beetles, and carrot flies. Use cuttings to place by the
crowns of carrots for carrot flies. Zones 6 and colder can overwinter
rosemary as houseplants or take cuttings.
RUE:
Deters aphids, fish
moths, flea beetle, onion maggot, slugs, snails, flies and Japanese
beetles in roses and raspberries. Companions for rue are roses, fruits
(in particular figs), raspberries and lavender. To make it even more
effective with Japanese beetles: crush a few leaves to release the
smell. Has helped repel cats for us. You should not plant rue near
cucumbers, cabbage, basil or sage. A pretty perennial with bluish-gray
leaves. May be grown indoors in a sunny window. Rue may cause skin
irritation in some individuals.
Remedy: See cats and dogs: Rue spray.
RYE:
An excellent use of
plant allelopathy is the use of mow-killed grain rye as a mulch. The
allelochemicals that leach from the rye residue prevent weed
germination but do not harm transplanted tomatoes, broccoli, or many
other vegetables.
SAGE:
Use as a companion
plant with broccoli, cauliflower, rosemary, cabbage, and carrots to
deter cabbage moths, beetles, black flea beetles and carrot flies. Do
not plant near cucumbers, onions or rue. Sage repels cabbage moths and
black flea beetles. Allowing sage to flower will also attract many
beneficial insects and the flowers are pretty. There are some very
striking varieties of sage with variegated foliage that can be used
for their ornamental as well as practical qualities.
More on sage.
SOUTHERNWOOD:
Plant with cabbage,
and here and there in the garden. Wonderful lemony scent when crushed
or brushed in passing. Roots easily from cuttings. Does not like
fertilizer! It is a perennial that can get quite bushy. We have
started to cut it back every spring and it comes back in not time. A
delightful plant that is virtually pest free.
SOYBEANS:
They add nitrogen to
the soil making them a good companion to corn. They repel chinch bugs
and Japanese beetles. Soybeans are so good for you! They are many ways
to prepare them.
SPINACH:
Strawberry, Fava Bean
SQUASH:
Companions: Corn,
cucumbers, icicle radishes, melon and pumpkin. Helpers: Borage deters
worms, improves growth and flavor. Marigolds deters beetle. Nasturtium
deters squash bugs and beetles. Oregano provides general pest
protection.
Incompatible with: Irish Potato
STRAWBERRY:
Friends are beans,
borage, lettuce, onions, spinach and thyme. Foes: Cabbage. Allies:
Borage strengthens resistance to insects and disease. Thyme, as a
border, deters worms.
SUMMER
SAVORY:
Plant with beans and
onions to improve growth and flavor. Discourages cabbage moths,
Mexican bean beetles and black aphids. Honey bees love it.
SUNFLOWERS:
Planting sunflowers
with corn is said by some to increase the yield. Aphids a problem?
Definitely plant a few sunflowers here and there in the garden. Step
back and watch the ants herd the aphids onto them! We have been doing
this for years and it is remarkable. The sunflowers are so tough that
the aphids cause very little damage and we have nice seed heads for
our birds to enjoy! Talk about a symbiotic relationship!
SWEET
ALYSSUM:
Direct seed or set out
starts of sweet alyssum near plants that have been attacked by aphids
in the past. Alyssum flowers attract hoverflies whose larva devour
aphids. Another plus is their blooms draw bees to pollinate early
blooming fruit trees. They will reseed freely and make a beautiful
groundcover every year.
TANSY:
Plant with fruit trees, roses and raspberries keeping in mind that it
can be invasive and is not the most attractive of plants. Tansy which
is often recommended as an ant repellant may only work on sugar type
ants. These are the ones that you see on peonies and marching into the
kitchen. At least for us placing tansy clippings by the greenhouse
door has kept them out. Deters flying insects, Japanese beetles,
striped cucumber beetles, squash bugs, ants and mice! Tie up and hang
a bunch of tansy leaves indoors as a fly repellent. Use clippings as a
mulch as needed. Don't be afraid to cut the plant up as tansy will
bounce back from any abuse heaped on it! It is also a helpful addition
to the compost pile with its' high potassium content.
·
Tansy Warning:
You do not want to plant Tansy anywhere that livestock can feed on it
as it is toxic to many animals. Do not let it go to seed either as it
may germinate in livestock fields.
TARRAGON:
Plant throughout the
garden, not many pests like this one. Recommended to enhance growth
and flavor of vegetables.
THYME:
Deters cabbage worms.
Wooly thyme makes a wonderful groundcover. You may want to use the
upright form of thyme in the garden rather than the groundcover types.
Thyme is easy to grow from seeds or cuttings. Older woody plants
should be divided in spring.
TOMATOES:
Tomato allies are
many: asparagus, basil, bean, carrots, celery, chive, cucumber,
garlic, head lettuce, marigold, mint, nasturtium, onion, parsley,
pepper, marigold, pot marigold and sow thistle. Basil repels flies and
mosquitoes, improves growth and flavor. Bee balm, chives and mint
improve health and flavor. Borage deters tomato worm, improves growth
and flavor. Dill, until mature, improves growth and health, mature
dill retards tomato growth. Enemies: corn and tomato are attacked by
the same worm. Kohlrabi
stunts tomato growth.
Incompatible with: potatoes,
cabbage and cauliflower. Keep Irish Potato, Fennel, Cabbage Family
apart from tomato as
they both can get early and late blight contaminating each other.
TURNIP:
English Pea ,
Incompatible with Irish
Potato
WHITE GERANIUMS:
These members of the
pelargonum family draw Japanese beetles to feast on the foliage which
in turn kills them.
WORMWOOD:
Keeps animals out of
the garden when planted as a border. An excellent deterrent to most
insects. A tea made from wormwood will repel cabbage moths, slugs,
snails, black flea beetles and fleas effectively. The two best
varieties for making insect spray are Silver King and Powis
Castle.
Adversely Powis castle attracts ladybugs which in turn breed directly
on the plant. Silver Mound is great as a border plant and the most
toxic wormwood. Note: As wormwood actually produces a botanical poison
do not use it directly on food crops.
See
More on wormwood. for more details.
For insect spray:
See wormwood spray
YARROW:
Yarrow has insect
repelling qualities and is an excellent natural fertilizer. A handful
of yarrow leaves added to the compost pile really speeds things up.
Try it! It also attracts predatory wasps and ladybugs to name just
two. It may increase the essential oil content of herbs when planted
among them.
NOTE: I take no
responsibility you getting sick from eating plants you have picked in
the wild or grown yourself. You gotta really know what you are doing.
That's YOUR job.
