By Farah Masani
Today I walked passed my nasturtiums and noticed they were coated in a layer of black aphids. (See photo.) This made me happy.
I was pleased to see the aphids were on my nasturtiums and not on my beans planted in the same bed. Aphids are plant lice and enemies of farmers. They’re plant destroyers. The nasturtium plant, with its bi-colored leaf and bright orange flowers, was more attractive to the aphid. Who would not find this plant attractive?
This is what these “attractive” plants do. They attract pests away from the “real crop” you are trying to grow. They are the protectors. They are sacrificial in nature. They are traps and commonly known as trap crops.
Ever notice sunflowers growing in a cotton field? Or onions and garlic growing beside carrots? Or a field inter-planted with different flowers, herbs and plants like marigold, nasturtiums, Indian mustard, Chinese cabbage, basil, castor.
Ever wonder why these are planted so close to one another? While these inter-plantings are pleasing to the eye and are visually grand out in the field – tall sunflowers swaying in the field of cotton (an image from back home I cannot get out of my mind) – they always have a purpose.
Different trap crops are planted at different times of the year based on the life cycle of the pests they attract. For example, you will often find chervil inter-planted amongst several vegetable crops, based on when they fruit, to attract slugs and keep them away from the vegetable you are trying to grow.
Nasturtium attracts black aphids and white aphids and keeps them away from beans and leafy greens, respectively. Horseradish inter-planted with potatoes keeps the potato beetle away.
You can interplant – i.e. plant intermittently – amongst your crop or you can grow around the perimeter. For example surround cabbage with collards – it attracts the cabbage moth. Or grow Blue Hubbard around yellow squash and you will keep the cucumber beetle away.
Planting these trap crops leads to less use of pesticides and chemicals, resulting in a healthier environment and better quality crop. It is also a cheaper alternative for the farmer. While trap crops “trap” the unwanted insects – the pests of the garden – they also attract the wanted insects – the insects beneficial to the garden.
For more info on beneficial plants and insects, stay tuned for next week’s article “The Benefits of Beneficials.”
Farm Masani is a farmer living in Wilton, CT who recently joined the staff of Barcelona Restaurant Group where she is responsible for local sourcing. In July she launched the Barcelona Farmigo CSA program to provide the restaurant’s patrons and greater community with a convenient and flexible way to purchase more sustainably grown local food. Farah previously worked as a farm manager at Millstone Farm in Wilton.