Growing a vegetable garden is one of the best ways to lower food costs and ensure that you’re getting fresh, locally produced, organic fruits and vegetables. But organic gardeners have to find creative ways to combat disease and insects that will eat their crops. I learned today that one of my favourite flowers, nasturtium, is also a companion plant for a really wide variety of vegetables – and fruit trees too!
Companion plants can help to control insects by repelling them or making it difficult for them to find the host plants they feed on, or by acting as a trap plant that will lure hungry pests away from your food crops. Nasturtiums can do all of these things. And if you grow this plant with your tomatoes, cucumbers, lettuces and other plants, you can also pick its peppery flavoured leaves and sweet tasting flowers, and enjoy them in a salad or other dish alongside your vegetables!
According to the Cornell University Extension guide to companion planting, nasturtiums are good companions to a large number of plants in both the cucurbit and cabbage families. Nasturtium will repel a large number of insect pests such as aphids, slugs, and a variety of predatory beetles. They can also be planted as a trap crop that will lure away insects such as cabbage white butterflies (Pieris rapae and Pieris brassicae) and thrips (order Thysanoptera.) Rodale also suggests that nasturtiums provide a habitat for predatory insects like ground beetles and spiders, that will munch on insects pests.
Using Nasturtium to Grow Healthier Cucumbers
The cucurbit family consists of not only cucumbers, but also summer and winter squash, pumpkins, gourds, and melons. Many of these crops are improved by planting nasturtiums as a companion. Nasturtiums repel cucumber beetles (genera Diabrotica and Acalymma,) squash bugs (Anasa tristis,) and whiteflies (family Aleyrodidae) which attack the plants in this family.
Plant the flowers as a border around your cucumber patch, or simply allow them to creep in among the vines. They will provide ground cover between the plants, which also helps to deter insect pests. And of course, the gorgeous orange and red flowers will look fabulous growing side by side with the yellow cucurbit blossoms!
How Nasturtium Helps Plants in the Cabbage Family
A wide variety of plants belong to the cabbage (brassica) family. You probably know that cauliflower, broccoli and Brussels sprouts are brassicas, and you may also have made the connection with plants like kale. But did you know that kohlrabi, turnip, watercress, canola, and mustard are all brassicas too?
Nasturtiums repels aphids and the cabbage looper (Trichoplusia ni) when planted near vegetables in the cabbage family. You can also use them as a trap crop for cabbage white butterflies, which will attack the nasturtiums instead of your brassicas.
Nasturtium as a Companion Plant for the Nightshade Family
Many of us associate nightshade with poison, but there are several food crops that belong to this family as well. Tomatoes, potatoes and eggplant all belong to this family, as do chili and bell peppers. Plants in this family can fall prey to flea beetles and Japanese beetles. Tomatoes are also plagued by aphids and whiteflies, while potatoes can be attacked by Colorado potato beetle. Planting nasturtium around your nightshades can help to repel all of these pests.
Protect Your Fruit Trees with Nasturtiums
Nasturtiums will protect a large number of fruit from the Japanese beetle (Popillia japonica.) Many fruit crops are in the rose family. Think apples, cherries, peaches, pears, plums, blueberries, raspberries, strawberries and many other berries. Plant nasturtiums in a ring around the trunk of these fruit trees, or interplant them with crops like blackberries and raspberries. I think it would be very cool to plant trailing nasturtiums with strawberries in an overhead trellis!
Other Vegetables That Grow Well with Nasturtium
These vegetables can also be helped with a companion planting of nasturtiums:
Asparagus – Nasturtium repels asparagus beetle (genus Crioceris)
Beans, Peas, and other Legumes – Repels flea beetle (tribe Alticini,) Japanese beetle, Mexican bean beetle (Epilachna varivestis)
Carrot – Repels carrot fly
Celery – Use nasturtium as a trap plant for thrips
Corn – Repels flea beetle and Japanese beetle
Lettuce – Repels flea beetle
Radishes – Use as a trap crop for cabbage white butterflies