Companion planting is an organic method of controlling pests and maintaining soil health. By growing certain plants next to, around or even interspersed with broccoli, you can minimize the effects of a number of pests without resorting to the use or pesticides. In addition, growing plants like chervil, chives or oregano with your broccoli can provide an interesting herb to sprinkle on freshly steamed broccoli.
Companion planting has been practiced since prehistoric times in cultures where farmers discovered the beneficial nature of planting certain crops together. A common practice among many American Indian cultures, it was shared with early European settlers. Companion planting lost some popularity as chemical fertilization became common. As an interest in organic gardening re-emerges, companion planting techniques are becoming more popular again for pest control.
Chervil is a companion plant for broccoli. According to Ghorganics, it improves growth and flavor and helps to keep aphids away. Chervil is a leafy vegetable that grows well in partial shade. It's best to seed chervil directly in the soil because it does not transplant well. Chervil can grow to between 1 and 2 feet tall. The leaves are parsley-like with an anise-type flavor. Try steaming your broccoli and sprinkling it with fresh, unsteamed chervil for an interesting flavor combination.
Nasturtiums are flowers that are edible and are sometimes used in salads. Nasturtiums deter aphids, squash bugs and stippled pumpkin beetles. They can also deter wooly aphids, whiteflies and cucumber beetles. In addition to the flowers, the leaves and seeds are also edible and often eaten in salads.
Chives drive away aphids, Japanese beetles and rust flies. They are recommended by Ghorganics as a companion plant for broccoli. However, in some cases, the chives may need to be established for a couple of years to be fully effective. Chives belong to the same family of plants as onions, leeks and garlic. They grow best in full sun but can survive in partial shade. The leaves of the plant have a mild, onion-like flavor.
Oregano is a very popular and common spice, often used in Italian cuisine. Oregano as a companion plant for broccoli is a good cabbage butterfly repellent. Oregano is a perennial herb. There are a number of varieties of oregano, but most grow in clumps of 8 to 10 inches in height and diameter. Dig up and divide oregano every two to three years to improve its flavor.
Companion planting discourages pests but does not always eliminate them. In a particularly heavy infestation of a pest, its numbers may overwhelm the companion plant's deterrent abilities. You may need to use alternative methods of pest control, such as predator insects or even chemical pesticides.