What you need to know:
Some garden plants do not thrive when grown in close proximity. Find out why and which plants do not make good companions in the backyard or the farm.
For almost every vegetable you will grow, there are companion plants to grow with them. This is referred to as companion planting. Vegetables are not the only plant types that can benefit from this practice, as ornamentals such as flowers can also reap from it.
Jude Tenywa, a gardener, says the practice is not founded so much on scientific facts but rather observations. “As we study how our crops are faring in our gardens, we get to notice certain things such as pest and disease concentrations. These give a farmer basis to make certain decisions. As such, there is a lot of trial and error before some planting combinations are arrived at,” says Tenywa.
He adds that understanding that plants depend on one another and are connected makes the observations worth it and the choices made get better with time.
Therefore, there is varying information from the various farmer experiences. However, Tenywa says there are a few unshakeable truths such as legumes being incompatible with members of the onion (allium) family.
Benefits of companion planting
There is a lot of good that can come from intercropping certain plants with others.
Some plants can attract beneficial insects such as bees to pollinate their flowers. “It goes without saying that those around them will benefit something they could have missed out had they been on their own,” Tenywa says.
On the other hand, some plants deter pests thus acting as insect repellents. For example, onions and garlic keep aphids away. He adds that other plants fend off predators such as snails.
Sandra Bonabana, a gardener says some plants help in improving soil fertility such as legumes which improve nutrient supply as well as its availability.
Bonabana adds that planting tall plants with short or creeping ones avails the latter with shade. “For example, corn (or maize) helps lettuce, which detests lots of heat. Creeping plants also benefit from the tall ones as they act as trellises.”
Mistakes to avoid
There are also certain plants that need not be planted together with others. Here are mistakes to steer clear from:
Plants that are susceptible to similar plant diseases and pests such as blight and aphids respectively should not be planted with each other. “Otherwise, there will be spread of these thus destruction of the whole garden,” Bonabana says.
Plants that compete for the same nutrient needs such as sunshine, space, soil nutrients, and water should never be planted together. Tenywa shares that when planted together, such plants will suffer stunted growth.
Another mistake worth steering away from is planting crops with those that hinder their growth. Tenywa says one of these is fennel which is the worst companion plant and therefore should never be planted with others.
Aside from benefits and mistakes, Bonabana shares that it is also important that a gardener follows crop rotation guidelines. “It is not good to plant a crop in the same place for consecutive seasons because it will deplete all the necessary nutrients. Moreover, disease and pests will also thrive with time. In due course, the yield will not be satisfactory,” she notes.
Here are some combinations that you could try:
These are friends with basil as it helps to repel spider mites, flies, aphids, and mosquitoes. “There is also a school of thought that basil will better the flavour of peppers. Other great companions include tomatoes, onions, and spinach,” Conrad Bate, a gardener shares. However they should not be planted with beans to prevent their vines from affecting the pepper growth.
Cabbage and other cole crops (broccoli, Brussels sprouts, collard greens, kale, and turnips) are best clustered with other cole crops such as onions, potatoes.
“Onions are a major must-have because they will keep aphids away. On the flip side, these cole crops should not be planted with pole beans, strawberries, and tomatoes. The issue with tomatoes is that both cole crops and tomatoes suffer with aphids,” Rita Rusoke, a gardener shares.
Beans are creeping plants and if you desire a bumper yield, Rusoke says you should plant them near corn/maize. “That will save you from building trellises. In the case of the corn, it will benefit from the beans that add nitrogen to the soil. Other compatible plants include rosemary and marigold as these keep beetles away. That is not forgetting cole crops, broccoli, peas, potatoes, eggplants, strawberries, radishes, Brussel sprouts, and cucumber,” Bate says.
On the other hand, beets and plants from the onion family (garlic, chives, scallions, leeks, and onions) should not be planted with beans. “Onions, in particular, impede the growth of bean plants because they release a substance into the soil that kills the beneficial bacteria on their roots. This hampers their growth while also preventing the beans from putting nitrogen into the soil.”
These sulphur filled plants are best planted with crops such as carrots because onions repel the carrot fly. “It is advisable to plant onions alongside any other onion friendly plants that are prone to aphids such as cabbage and other cole crops, lettuce, tomatoes, and spices such as rosemary, and marjoram. Parsnips will also benefit because they are affected by carrot fly,” Tenywa says. On the other hand, never be planted alongside beans, peas and asparagus.
A mixture of basil and tomatoes is an ingredient for an amazing vegetable salad. In like manner, when these two are planted together, Batte says they make great companions enabling the tomatoes yield greatly as basil repels mosquitoes and flies. “Marigolds are great for intercropping because they repel nematodes and other pests. Other plants include spinach, asparagus, cucumber, celery, lettuce, parsley and the onion family.”
Unfriendly plants include beets, dill, peas, rosemary, corn, and cabbage.
“Corn and tomatoes cannot be mixed because they are both attacked by earworm while potatoes also suffer blight,”says Batte.
The plants that produce these juicy vegetables are susceptible to beetles and aphids. That is why Tenywa says planting them with marigolds is an amazing idea.
“Other great companion plants are radishes, celery, onions, beans, beets, dill, lettuce, and corn. However, they cannot do well when planted alongside aromatic herbs such as rosemary as these stunt their growth. Others are potatoes and melons as both are affected by aphids and beetles,” Rusoke shares.
Seeing that tomatoes provide shade, they are amazing companion plants to carrots which are sensitive to heat. Batte says tomatoes also produce a substance called solanine, which is a natural insecticide targeting pests that affect carrots.
“Carrots are not the only beneficiaries as they aerate the soil around their roots as well as those of tomatoes which allows more air and water to reach the roots. “Carrots and leeks also make great companions because carrots repel leek moths and onion flies while leeks repel carrot flies. Other companion plants include chive, sage and rosemary which also help repel carrot flies. Beans and peas, owing to nitrogen fixing in the soil makes them great companions,” he says.
On the other hand, plants such as dill and coriander produce compounds that can harm carrot plants while parsnips and parsley suffer from similar pests and diseases as carrots. “As such planting them apart is important,” he advises.
While these detest potatoes because both are attacked by blight, zucchini flourishes when planted with corn because the cornstalks offer the zucchini vines a trellis. Rusoke adds that they do well with corn, peas, marigolds, dill, peas, beans and radishes.
Flowers as companion plants
Planting flowers in your garden is not just for the aesthetic values because Zulfa Karungi, a florist says annuals such as sunflower and marigold as well as perennials such as lavender repel pests while attracting beneficial insects.
Lettuce flourishes when planted with mint as it keeps pests such as slugs at bay. You could also plant it with radishes, corn, squash, broccoli, beans, and beets. “Marigolds are also great because they attract aphid-eating ladybugs while chives and garlic totally repel aphids,” Tenywa says.
However, lettuce should never be planted with parsley because it can grow into bushy plants which overcrowd it. Cole crops are also not a good idea because they are also attacked by aphids.