CARROTS LOVE TOMATOES
By Louise Riotte
The A to Z Guide to Companion Planting for
Healthier Plants and Bigger Harvests
THE MAGIC AND MYSTERY OF companion planting has intrigued
and fascinated men for centuries, yet it is a part of the
gardening world that has never been fully explored. Plants
that assist each other in growing well, that repel insects,
or that even repel other plants are all of great practical
use, but we're just beginning to find out why. In the years
to come I hope scientists, gardeners, and farmers
everywhere will work together to make discoveries that will
prove of great value in augmenting the world's food supply.
Already, companion planting has produced insect- and
disease-resistant fruits, grains, and vegetables, and
experiments are being conducted on weed-resistant
varieties.
A major enemy of the carrot is the carrot fly, whereas the
leek suffers from the leek moth and the onion fly. Yet when
they live in companionship, the strong and strangely
different smell of the partner plant repels the insects so
well that they do not even attempt to lay their eggs on the
neighbor plant. This is why mixed plantings give better
insect control than a monoculture where many plants of the
same type are planted together in row after row.
It's the same with kohlrabi and radishes in their community
life with lettuce. Both are often afflicted by earth flies,
but when the flies get the odor of lettuce they take off.
Even when plants are affected by diseases one can usually
alleviate the situation with a mixed plant culture.
All through this article you will find "what to grow with"
and "what not to grow with." Both are equally
important to gardening success. The following suggestions
for companion planting are only a beginning. Your own
experiments will lead you toward many different pathways
and discoveries.
Asparagus ( Asparagus officinalis
). Parsley planted alongside asparagus gives added vigor to
both. Asparagus also goes well with basil, which itself is
a good companion for tomatoes. Tomatoes will protect
asparagus against asparagus beetles because they contain a
substance called solanine. But if asparagus beetles are
present in great numbers, they will attract and be
controlled by their natural predators, making spraying
unnecessary. A chemical derived from asparagus juice also
has been found effective on tomato plants as a killer of
nematodes, including the root-knot sting, stubby root, and
meadow varieties.
In my garden, I grow asparagus in a long row at one side.
After the spears are harvested in early spring, I plant
tomatoes on either side, and I find that both plants
prosper from the association. Cultivating the tomatoes also
stems weed growth around the asparagus. The asparagus
fronds should not be cut much, if at all, until very late
in the fall, as the roots need this top growth to enable
them to make spears the following spring.
Bean ( Phaselolus and Vicia ).
Many different kinds of beans have been developed, each
with its own life of "good" and "bad" companions. Generally
speaking, however, all will thrive when interplanted with
carrots and cauliflower; carrots especially help the beans
to grow. Beans also grow well with beets as well as
cucumbers and cabbages.
A moderate quantity of beans planted with leek and celeriac
will help all, but planted too thickly they have an
inhibiting effect—causing poor growth for all three.
Marigolds in bean rows help repel the Mexican bean beetle.
Planting summer savory with green beans improves their
growth and flavor as well as deterring bean beetles. (It is
also good to cook with beans.)
Beans are inhibited by any member of the onion
family—garlic, shallots, or chives—and they
also dislike being planted near gladiolus.
Broad beans are excellent companions to corn, climbing
diligently up the corn stalks to reach the light. They not
only anchor the corn more firmly, acting as a protection
against the wind, but a heavy vine growth may also act as a
deterrent to raccoons. In addition, beans provide the soil
with nitrogen, which enriches corn growth.
Bean and Potato . Bush beans planted with
potatoes protect them against the Colorado potato beetle.
In return, the potatoes protect the bush beans from the
Mexican bean beetle. It is considered best to plant the
beans and potatoes in alternate rows.
Bean, Bush ( Phaseolus vulgaris
). Included with bush beans are those known as butter,
green, snap, string, or wax. All will do well if planted
with a moderate amount of celery (about one celery plant to
every six or seven of beans).
Bush beans and cucumbers are mutually beneficial. Bush
beans planted with straw berries also help one another,
both advancing more rapidly than if planted alone.
One gardener believes that celery is benefited if grown in
a circle so that the lacy, loosely interwoven roots make a
more desirable home for earth-worms and soil microbes.
Bush beans will aid corn if planted in alternate rows. They
grow well with summer savory but should never be planted
near fennel. They also dislike onions, as do all beans.
Bean, Lima ( Phaselous limensis
). Nearby locust trees have a good effect on the growth of
lima beans. Other plants give them little or no assistance
in repelling insects. Never cultivate lima beans when they
are wet, because if anthracnose is present, this will cause
it to spread. If the ground has sufficient lime and
phosphorous there will probably be little trouble from
anthracnose and mildew.
Bean, Pole . Like others of the family,
pole beans do well with corn and summer savory but they
also have some pronounced dislikes, such as kohlrabi and
sunflower. Beets do not grow well with them, but radishes
and pole beans seem to derive mutual benefit.
Bee Balm ( Monarda ). Improves
both the growth and flavor of tomatoes.
Beet ( Beta vulgaris ). Beets
grow well near bush beans, onions, or kohlrabi but are
"turned off by pole beans. Field mustard and charlock also
inhibit the growth of beets. Lettuce and most members of
the cabbage family are "friendly" to them.
Broccoli ( Brassica oeraceae ).
Like all members of the cabbage family, broccoli does well
with such aromatic plants as dill, celery, chamomile. sage.
peppermint, rosemary, and with other vegetables such as
potatoes, beets, and onions. Do not plant it with tomatoes,
pole beans, or strawberries. Use pyrethrum against aphids
but only before the flower buds open.
Cabbage ( Brassicaceae ). The
cabbage family includes not only cabbage but cauliflower,
kale, kohlrabi, broccoli, collards, and Brussels
sprouts—even rutabagas and turnips. While each plant
of this group has been developed in a special way, they are
all pretty much subject to the same likes and dislikes,
insects and diseases. Hyssop, thyme, wormwood, and
southernwood are helpful in repelling the white cabbage
butterfly.
All members of this family are greatly helped by aromatic
plants, or those which have many blossoms, such as celery,
dill, chamomile, sage, peppermint, rosemary, onions, and
potatoes.
If rabbits dig in your cabbage patch, plant any member of
the onion family alongside them. Or you can dust with
ashes. powdered aloes, or cayenne pepper. Rabbits also shun
dried blood or blood meal.
Butterflies themselves aren't harmful and can help
pollinate plants. It is their hatched eggs which as
caterpillars do such damage to the orchard and field crops.
The white cabbage butterfly is perhaps the most
destructive. Herbs will repel them: hyssop, peppermint,
rosemary, sage, thyme, and southernwood.
Cabbages dislike strawberries, tomatoes, and pole beans.
All members of the family are heavy feeders and should have
plenty of compost or well-decomposed cow manure worked into
the ground previous to planting. Mulching will help if the
soil has a tendency to dry out in hot weather, and water
should be given if necessary.
Cabbage and cauliflower are subject to clubroot. and if
this occurs try planting in new soil in a different pan of
the garden. Rotate cabbage crops every two years.
If cabbage or broccoli plants do not head up well, it is a
sign that lime, phosphorus, or potash is needed. Boron
deficiency may cause the heart of the cabbage to die out.
Celery ( Apium graveolens ).
Celery grows well with leeks, tomatoes, cauliflower, and
cabbage, while bush beans and celery seem to provide mutual
assistance. One gardener believes that celery is
particularly benefited if grown in a circle so that the
lacy, loosely interwoven roots may make a more desirable
home for earthworms and soil microbes. Celery and leeks
both grow well when trenched. Both celery and celeriac are
reported to have a hormone which has an effect similar to
insulin, making them an excellent seasoning for diabetics
or for anyone on a salt-reduced diet.
Corn ( Zea mays ). Sweet corn
does well with potatoes, peas, beans, cucumbers, pumpkin,
and squash. Research has shown that removing corn suckers
is a waste of time as well as being detrimental to the
development of the ears. Peas and beans help corn by
restoring to the soil the nitrogen used up by the corn. Is
there anyone who hasn't heard the story of Indians putting
a fish in every corn hill?
MeMelons, squash, pumpkins, and cucumbers like the shade
provided by corn. In turn they benefit the corn, protecting
it from the depredations of raccoons, which do not like to
travel through the thick vines. Similarly, pole beans may
be planted with corn to climb on the stalks. But don't
plant tomatoes near corn, because the tomato worm and corn
earworm are identical.
Also of note: An experiment with odorless marigold
showed that when it was planted next to corn the Japanese
beetle did not chew off the corn silks.
Cucumber ( Cucumis sativus ).
Cucumbers apparently are offensive to raccoons, so it's
beneficial to plant it alongside corn. And corn seemingly
protects the cucumbers against the virus that causes wilt.
Thin strips of cucumber will repel ants.
Cucumbers also like beans, peas, radishes, and sunflowers,
and—preferring some shade—they will grow well
in young orchards. Sow two or three radishes, but let them
grow as long as they will, even blossoming and going to
seed. Cucumber beetles also may be trapped by filling
shallow containers about three-quarters full of water into
which some cooking oil has been poured.
If cucumbers are attacked by nematodes, try a sugar spray.
I boil half a cup of sugar in two cups of water, stirring
until completely dissolved. Let cool and dilute with a
gallon of water. Strange as it seems, sugar kills nematodes
by drying them out. This will also attract
honeybees—insuring pollination and resulting in a
bumper crop of cucumbers—so the spray is worth trying
even if you don't suspect the presence of nematodes.
Cucumbers dislike potatoes, while potatoes grown near
cucumbers are more likely to be affected by phytophthora
blight, so keep the two apart.
Beneficial fungi are another enemy of nematodes. If you
suspect their presence, build up the humus content of your
soil. A chive spray is helpful for downy mildew on
cucumbers as is a spray made of horsetail.
Cucumbers dislike potatoes, while potatoes grown near
cucumbers are more likely to be affected by phytophthora
blight, so keep the two apart. Cucumbers also have a
dislike for aromatic herbs.
Plant scientists William Duke, of Cornell, and Alan Putnam,
of Michigan State University, have discovered that certain
cucumber varieties fight weeds by releasing a toxic
substance. This natural process—allelopathy—is
believed to be an inherited trait. Thus, attempts are being
made to incorporate weed resistance into commercial crops
much in the same way as insect and disease resistance is
bred into plants.
Eggplant ( Solanum melongena ).
Redroot pigweed makes eggplant more resistant to insect
attack. During dry weather, mulching and irrigation will
help prevent wilt disease. Dry cayenne pepper sprinkled on
plants while still wet with dew will repel caterpillars.
Eggplant growing among green beans will be protected from
the Colorado potato beetle. The beetles like eggplant even
more than potatoes, but they find the beans repellent.
Garlic ( Allium sativum ). Eldon
L. Reeves and S. V. Amonkar, of the University of
California, discovered garlic to be a powerful destroyer of
mosquitoes, achieving a 100% mortality of five species of
California mosquito larvae by spraying breeding ponds with
a garlic-based oil.
Researcher David Greenstock, of the Henry Doubleday
Research Association in England, found that a garlic-oil
emulsion, used as an insecticide, killed 89% of aphids and
95% of onion flies.
Here's a recipe for a good garlic spray: Take 3 to 4 ounces
of chopped garlic bulbs and soak in 2 tablespoons of
mineral oil for one day. Add a pint of water in which 1
teaspoon of fish emulsion has been dissolved. Stir well.
Strain the liquid and store in a glass or china container,
as it reacts with metals. Dilute this, starting with 1 part
to 20 parts of water, and use as a spray against your worst
insect pests. If sweet potatoes or other garden plants are
attracting rabbits, try this spray. Rabbits dislike the
smell of fish, too. Garlic sprays are useful in controlling
late blight on tomatoes and potatoes.
Garlic grown in a circle around fruit trees is good against
borers. It is beneficial to the growth of vetch, protects
roses, and, when cloves are stored in grain, will repell
grain weevils. All alliums , however, inhibit the
growth of peas and beans. Plant garlic with tomatoes to
protect against red spiders. I have done this for three
successive years, with good results.
Kohlrabi ( Brassicaceae ).
Kohlrabi grown with onion or beets, with aromatic plants,
and, surprisingly, with cucumbers, are mutually beneficial
in part because they occupy different soil strata. Kohlrabi
dislikes strawberries, tomatoes, and pole beans but helps
protect mustard family members.
Leek ( Allium porrum ). Leek is a
heavy feeder and should be planted in soil well-fertilized
with rotted manure. Leeks are usually sold in the grocery
store (at least where I live) with the roots still
attached. I once bought several bunches and planted them;
they grew well and propagated, and I've had leeks ever
since.
Leeks are good plants to grow with celery and onions, and
also are benefited by carrots. Returning the favor, leeks
repel carrot flies.
Lettuce: ( Lactuca saliva ) In
spring I kep a supply of small lettuce plants growing in
cold frames. When I pull every other green onion for table
use I pop in lettuce plants. They will aid the onions, and
the compost in the onion row will still be in good supply
for the lettuce to feed on, while the onion will repel any
rabbits.
Lettuce grows well with strawberries, cucumbers, and
carrots, and it has long been considered good to team with
radishes. Radishes grown with lettuce in summer are
particularly succulent.
Okra ( Hibiscus esculentus ).
This native of the Old-World tropics is grown for its
immature pods, which are called okra or gumbo. It's a
warm-weather plant which grows wherever melons or cucumbers
thrive. I plant two rows, dig a trench between, and cover
it with mulch. On the north side of my okra, I plant a row
of sweet bell peppers and on the south side a row of
eggplant. All are well mulched as the season advances. When
the weather becomes dry in midsummer I lay the hose in the
trench and flood it so that all three companions grow well.
Onion (Allium cepa). Onions and all
members of the cabbage family get along well with each
other. They also like beets, strawberries, tomatoes,
lettuce, summer savory, and chamomile (sparsely), but do
not like peas and beans.
Since onion maggots travel from plant to plant when set in
a row, scatter your onion plants throughout the garden.
Toxic substances in the pigments of red and yellow onion
skins appear to be associated with disease resistance.
Russian biologist T. A. Tovstole found a water solution of
onion skin—used as a spray three times daily at
five-day intervals—gave an almost 100% mortality of
hemitera, a parasite attacking more than 100 different
species of plants.
Parsley ( Petroselinum hortense
). Parsley mixed with carrot seed helps to repel carrot
flies by its masking aroma. It protects roses against rose
beetles. Planted with tomatoes or asparagus, parsley will
give added vigor to both.
Poultry are sometimes turned loose at intervals in parsley
patches where there are many parsley worms, which are the
larvae of the black swallowtail butterfly.
Parsnip ( Pastinuca sativa ) The
parsnip is of ancient culture, but remains a vegetable for
the discerning palate. The parsnips have few insect enemies
and suffer from few diseases, but both the foliage and
roots make a safe insect spray. They are not injured by
freezing and are often left in the ground over winter. The
seeds germinate slowly and unevenly and should not be used
if over a year old.
Pea ( Pisum sativum ). For large
crops, inoculate pea and bean seed with Nitragen (or
similar compound), which is a natural bacterial agent. It
coats the seed, aiding the sprouting seedling. This enables
the plant to more readily form nodules on the roots which
convert nitrogen from the air into a compound the plant can
use.
Peas grow well with carrots, turnips, radishes, cucumbers,
corn, beans, and potatoes, as well as many aromatic herbs.
They do not grow well with onions, garlic, and gladiolus.
Pumpkin ( Cucurhita pepo ).
Pumpkins grow well when jimson weed, sometimes called thorn
apple, is in the vicinity. Pumpkins grow well with corn (a
practice followed by Native Americans), yet pumpkins and
potatoes have an inhibiting effect on each other.
Radish ( Rubus ). If you grow
both red and black raspberries, put a considerable distance
between the two types. The reason for this is that the reds
sometimes carry a disease which does little or no harm to
themselves but may prove near fatal to the blacks. Do not
grow raspberries and blackberries near each other, either.
Potatoes are more susceptible to blight if grown near
raspberries, many gardeners believe.
Spinach ( Spinacia oleracea ).
Because of its saponin content, spinach is a useful
pre-crop and does well planted with strawberries.
Squash ( Curcubitaceae ). Two or
three icicle radishes planted in each hill will help
prevent insects on squash and on cucumbers. Let the
radishes grow and go to seed. Nasturtiums will repel squash
bugs and so will cigarette ash and other tobacco residue if
placed with the seed when it is planted. Squash planted
either earlier or later than usual often will escape insect
damage. I find fall-planted squash almost entirely
insect-free.
Early in the day before the sun is strong, squash stinkbugs
are sluggish, and in the small garden may be picked off.
There are also insect-resistant strains of squash
available.
Sweet Potato ( Ipomea batalas ).
Nemagold sweet potatoes developed by the Oklahoma
Experiment Station have built-in resistance to nematodes.
Sweet potatoes generally have high-energy value, with only
peas and beans yielding more. They have a common
enemy—the fungus disease or wilt called "stem
rot"—which can be controlled with disease-free seed
and by rotating the crop. White hellebore controls a number
of leaf-eating insects.
If rabbits bother your sweet-potato patch, spray with a
diluted fish emulsion. (Parks has one called Mer-Made Fish
Emulsion.)
Tomato ( Lycopersicon esculentum
). Tomatoes will protect asparagus against the asparagus
beetle. Since they are tender plants, put tomatoes in
during late spring after the early crop of asparagus spears
has been harvested. Tomatoes and all members of the
Brassica family repel each other and should be
kept apart. Tomatoes protect gooseberries against insects.
Tomatoes are compatible with chives, onion, parsley,
marigold, nasturtium, and carrot, and for several years I
have planted garlic bulbs between my tomato plants to
protect them from red spider mites. Though not containing
fungicidal elements, tomatoes will protect roses against
black spot.
The active principle of tomato leaves is solanine, a
volatile alkaloid that at one time was used as an
agricultural insecticide. You can create your own
insect-repellent spray for roses by making a solution of
tomato leaves in your vegetable juicer—add 4 or 5
pints of water and 1 tablespoon of cornstarch. Strain and
spray on roses where it is not convenient to plant tomatoes
as companions. Keep any unused spray refrigerated.
Unlike most other vegetables, tomatoes prefer to grow in
the same place year after year, and this is all right
unless you have a disease problem, in which case plant your
tomatoes in a new area. Stinging nettle growing nearby
improves their keeping qualities, and redroot pigweed, in
small quantities, is beneficial, too. Tomatoes are
inhibited by the presence of kohlrabi and fennel.
Root excretions of tomatoes have an inhibiting effect on
young apricot trees. Don't plant tomatoes near corn, since
the tomato fruitworm is identical to the corn earworm.
Don't plant near potatoes, either, since tomatoes render
them more susceptible to potato blight.
If you smoke, be sure to wash your hands thoroughly before
you work in your garden, for tomatoes are susceptible to
diseases transmitted through tobacco.
Turnip/Rutabaga ( Brassica rapa and
Brassica napobrassica ). An accident revealed that
hairy vetch and turnips are excellent companions. Turnip
seeds became mixed with the vetch a gardener planted, and
they came up as volunteer plants. He found the turnip
greens completely free of the aphids which usually infest
them, apparently because the vetch provided shelter for
ladybugs, which feast on aphids. Elsewhere it has been
found that wood ashes around the base of turnip plants will
control scab.
I find peas planted near turnips are mutually benefited.
Turnip and radish seed mixed with clover will bolster the
nitrogen content of the soil. In your crop rotation it is
good to follow the heavy feeders with light feeders such as
turnips and rutabagas.
Turnips dislike hedge mustard and knotweed, and should not
be rotated with other members of the cabbage family such as
broccoli or kohlrabi. When synthesized, a naturally
occuring chemical compound in turnips when synthesized is
deadly to aphids, spider mites, houseflies, German
cockroaches, and bean beetles.
Rutabagas take much the same culture as turnips but require
a longer growing season.
CONTROL OF INSECTS BY COMPANION PLANTING
Legumes planted in a rotation will protect grain crops and
grasses from white grubs and corn rootworm. Chinch bugs on
corn and flea beetles are controlled by growing soybeans to
shade bases of the plants. Goats with worms may be relieved
by feeding them carrots; in horses by feeding them mulberry
leaves.
The following herbs may be planted as specific control:
BASIL: Against flies and mosquitoes.
BORAGE: Against tomato worm.
CASTOR BEAN: Against moles and plant
lice.
CATNIP: Against flea beetles.
DATURA: Against Japanese beetles.
DEAD NETTLE: Against potato bugs.
FLAX: Against potato bugs.
GARLIC: Against Japanese beetle, aphis,
weevils, fruit tree borers, spider mites.
HENBIT: General insect repellent.
HORSERADISH: Against potato bugs (plant at
comers of plot).
HYSSOP: Against cabbage moth.
LAVENDER: Against clothes moths (dry and
place in garments).
MARIGOLDS: Against Mexican bean beetles,
nematodes and many other insects.
MINT: Against white cabbage moths, dried
against clothes moths.
MOLE PLANT: Against moles and mice (Mole
plant is a species of Euphorbia).
NASTURTIUM: Against aphids, squash bugs
striped pumkin beetles, woolly aphids.
PENNYROYAL: Against ants an plant
lice.
PEPPERMINT: Against white cabbage
butterflies, ants.
PETUNIA: Against beetles.
POT MARIGOLD: Against pickle-worms,
aphids, leafhoppers, spider mites, harlequin bugs, imported
cabbage worms and many other insects.
PYRETHURM: Against pickleworms, aphids,
leafhoppers, spider mites, harlequin bugs, imported cabbage
worms and ticks.
ROSE GERANIUM: Oil or crushed leaves as
insect repellants.
ROSEMARY: Against cabbage moths, bean
beetles, carrot flies, malaria mosquitoes.
RUE: Against Japanese beetles.
SAGE: Against cabbage moths, carrot flies,
ticks.
SANTOLINA: Against moths.
SASSAFRAS: Against plant lice.
SOUTHERNWOOD: Against cabbage moths,
malaria mosquitoes.
SPEARMINT: Against ants, aphids
STINGING NETTLE: Against aphids, black
flies.
SUMMER SAVORY: Against bean beetles.
TANSY: Against flying insects, Japanese
beetles, striped cucumber beetles, squash bugs, and
ants.
THYME: Against cabbage worms.
WHITE GERANIUM: Against Japanese
beetles.
WORMWOOD: Against animal intruders,
cabbage worm butterflies, black flea beetles, and even
malaria mosquitoes.