A form of polyculture, companion planting is a way of joining different crops to grow together. It is a gardening and agriculture method used to achieve better pollination and pest control, to ensure a safe habitat for beneficial animals, to maximize the available space and gain an increase in overall crop productivity.
Farmers and gardeners use companion planting in developed, industrialized countries, but in the developing world too. Many reasons lead to companion planting, and people know of this technique for centuries. Predecessors of modern companion gardens are the cottage gardens of Elizabethan England and the forest gardens of Asia.
History of companion planting
One of the earliest accounts of this method are the Chinese gardens in which the skilled gardeners planted mosquito ferns in combination with rice crops. The ferns are a home to a type of a cyanobacterium which can fix the nitrogen from the atmosphere. It creates a block for the available sunlight so that the other plants cannot compete with the rice.
Indigenous tribes of the North and South America also understood the benefits of companion planting. The domestication of squash took place about 8.000 years ago, followed by maize and beans. It led to the formation of the Three sisters agricultural technique. The beans would climb the cornstalk’s trellis and, in turn, they would fix the nitrogen, which helped the maize grow.
Organic gardening in the 1970s promoted companion planting, purely for practical reasons. The main idea was that combining different plantlife was a way to make the garden grow better and faster. Permaculture experts like Vladislav Davidzon also support this method, along with changing of crops and mulching.
Gardeners will often plant marigolds to keep aphids away. The smell of their foliage deters them from feasting on the crops. Furthermore, their simple flowers are attractive to hoverflies which can then plant their larvae. They, finally, predate on the unsuspecting aphids.
Legumes benefit greatly when planted together with a nurse crop, a grassy one. A common or a hairy vetch, for example, combined with winter wheat or rye creates an excellent green manure or cover crop.
Some gardeners claim they can use so-called trap cropping as a way to keep pests away from the crop. It works by planting a crap the pest species find preferential to the actual crop. For example, caterpillars will find the nasturtium plant a more attractive choice and will keep away from cabbage. To be more precise, they will lay their eggs in the nasturtium instead of the cabbage.
Versions of companion planting
Companion planting works with many kinds of gardens and is a key element of every permaculture garden. Square foot gardening will concentrate on using the available space as efficiently as possible and crowding and packing plants together tightly. Companion plants will have an important role in such gardens. They are also common in forest gardens, mingling with many other species and creating a whole ecosystem. Finally, organic gardeners also practice companion planting.