COMPANION PLANTING - The Basic Concepts

‘Companion planting’ is planting vegetables, herbs and flowers together which benefit one another in several ways. Companion planting brings together the observations and experiences of countless generations of gardeners and farmers. Through trial, error and success, we are able to utilize nature’s gifts to their fullest extent. Companion planting increases biodiversity and creates an ecosystem for all plants to survive and thrive.

Many plants have natural substances in their roots, flowers, leaves and stems that can repel (anti-feedents) and/or attract insects, depending upon your needs. Some species procude chemicals that stimulate the productivity and growth of other species within it’s vicinity. Other plants are able to have an impact on diseases, predators and pests and can offer protection to other plants around them.

Companion planting enhances the growth rate and flavour of other plant varieties within the garden. Companion planting throughout a garden is an important part of integrated pest management and helps bring a balanced eco-system to your landscape, allowing nature to take it’s natural course.

By using Companion Planting we are able to discourage harmful pests without losing the beneficial allies. There are countless plants, herbs and flowers that can be used as companion plants. Use plants as a backdrop, border or inter-planting in between vegetables and flower beds where you have specific needs.

Be open to experimenting throughout the seasons. Preferably use plants that are native to your area as the insect species of your area are familiar with what to look out for.

Companion planting combines beauty with purpose, and gives us a healthy, enjoyable and healing environment.

Feel free to enjoy experimenting in your garden. What works for one gardener may not necessary work for another and some suggestions may work differently (or not at all) due to differing climates, soil conditions, water, weather etc etc ... Experimenting is a great way to gain new insight for your own individual gardens.

BARRIER CROPS

Companion plants can be used to hedge beds of vegetable and inter-planted between rows. Lettuce and peas can be separated by rows of chives and garlic to prevent insect attack.

SPATIAL INTERACTION

Tall-growing, sun-loving plants may share space with lower-growing, shade-tolerant species, resulting in higher yields. Spatial interaction also has pest control benefits.

For example, the diverse canopy resulting when corn is companion-planted with pumpkins or squash is believe to disorient the adult squash vine-borer and protect the vining-crop from this pest.

Spatial interaction is basically planting a wide variety of species that confuse predatory insects. The insects’ senses are confused by the signals emitted by the diverse plantings, making it difficult for the insect to locate their desired crop.

NURSE CROPPING

One of the simplest, most beneficial effects offered by companion planting is physical, such as offering shelter from the wind and wind. A high or large canopy above may offer protection to emerging plants below.

Other plants have long tap roots that help break up and aerate heavy and compacted soils.

Growing some species of plants (groundcovers) as weed suppression is another form of ‘nurse-cropping’. Nurse crops such as oats have long been used to help establish alfalfa (or lucerne) by supplanting the more competitive weeds that would otherwise grow in their place.

BENEFICIAL HABITATS

Beneficial habitats are another type of companion planting method, whereby the benefits are derived when the plants provide a desirable environment for beneficial insects and other arthropods to survive and thrive.

PLANTS THAT RETRIEVE NUTRIENTS

Some plant species offer benefits to surrounding plants by way of their long roots. These plants draw up nutrients from deep within the ground and actively accumulate elements useful for other plants. An example of this is Buckwheat, which is a species that accumulates calcium for the benefit of the other plants around it.

NITROGEN FIXING PLANTS

Legumes such as beans, peas and clover, have the ability to fix atmospheric nitrogen for their own use and the for the benefit of neighbouring plants. This is achieved via a symbiotic relationship with ‘Rhizobium’ bacteria.

Some species of plants, such as peas, beans, legumes, lucerne (alfalfa) and various clovers offer beneficial effects to surrounding plants by improving the fertility of the soil, and as a result, the yield and health of the plants grown alongside them.

Nitrogen fixing plants take nitrogen directly from the atmosphere, then converts it to soil-enriching nitrogen compounds.

GREEN MANURES

Green manures and nutritional mulches consist of plants such as those of the Papilionaceae family – sweet peas, bauhinias, mimosoideae. This species have toots with nitrogen from the soil and converts it to available form for the plants to use as food. Lupins, peanuts and clover also fall into this category.

TRAP PLANTING – Trap Cropping

Companion planting includes the use of a method known as ‘trap cropping’. Plants are grown and used to lure undesirable insects away from vulnerable species. Other plants then act as a refuge to beneficial insects including hoverflies, lacewings, predatory mites, ladybirds (ladybugs) and various species of wasps.

Some companion plants can be used as attractants or ‘trap plants’ to act as bait and draw a particular pest away from a crop onto another plant. In effect, these trap plants will be sacrificed for the good of the main crop.

ATTRACTANTS

Attract beneficial insects by dotting parsley, dill, lavender and perfumed shrubs throughout the garden.

Plant borage, dill, German chamomile, nasturtium, pineapple sage and elder to attract grub and insect eating birds into the garden.

INSECT REPELLING PLANTS

Some plants exude chemicals from their roots or aerial parts that suppress or repel pests and protect neighbouring plants. The roots of some plants exude a variety of active chemicals which repel nematodes (microscopic worms that burrow into the tissue of plants such as tomatoes).

Some species of plants are known for their excellent insect repelling qualities. Such plants are sage, rosemary, southernwood, lavender, thyme, sweet marjoram, hyssop, nasturtium, tansy, pennyroyal and chives.