Photo Credit Rebecca Anne Cole
Nasturtium, also known as Indian cress, is a climbing annual plant, with vines reaching up to 10 feet in length. The intricate flowers mature into impressive displays of yellow, orange, and red. The dainty flowers, leaves, and green shoots are edible, and have a peppery flavor similar to watercress. Leaves may be used like lettuce, and the vibrant flowers make for a colorful garnish.
I ended up with several packets of nasturtium blend by accident after an online checkout order went awry. I had refreshed the page one too many times to unstick the frozen screen and ended up with multiple orders. Thankfully the page was stuck on the $2.49 nasturtium seed packets and not the elaborate high dollar cucumber trellis I had been wistfully contemplating.
I scattered a few nasturtium seeds in my front garden bed in between sweet potato slips and perennial herbs, then pretty much forgot about them. Once the seeds germinated and the vines began to spread, the round green leaves provided a useful groundcover, acting as an umbrella to shade the waning weeds underneath. The bed required minimal weeding most of the season.
It wasn’t until the flowers started to bloom in showy vibrant hues of yellow and orange that I fully appreciated the beauty of the plant. Only afterwards when I did some research on nasturtium did I understand their value in the garden for insect control. Nasturtium are natural repellents to many unwanted garden insects, including beetles, aphids, cabbage worms, and slugs.
Based on my research, two theories emerged as to how and why nasturtium is effective with unwanted insect control. The first theory infers that the plant repels bugs by expelling a chemical that many garden pests find intolerable. Contrary belief suggests that pests are actually attracted to the plant, preferring nasturtium to other options, thus serving as a diversion to spare vegetable crops when planted near them. I plan on further researching these theories first-hand in my garden, but either way nasturtium is a natural option for insect control.
This season I am inter-planting nasturtium with my brassicas, which suffered a terrible fate at the hands of cabbage beetles last fall. I lost an entire crop to the voracious bugs whose insatiable appetites were not satisfied until each and every plant had been stripped clean. At first I thought rabbits were taking their nibbles, but by the time I realized it was in fact beetles the entire crop was lost. I plan to monitor whether the insects are repelled from the companion planted bed altogether, or if they prefer to feast on the nasturtium, sparing the cabbage and broccoli.
Nasturtium do best when directly sown in place about two weeks before the last threat of frost, but they may be started indoors for transplant a few weeks earlier. Seeds are planted 1 to 2 inches deep, about 3 inches apart. Look for seeds to germinate in about 10 to 14 days, then thin seedlings to about 10 to 12 inches apart. Vines may reach up to 10 feet in length and may be trellised or allowed to spread on the ground, which can act as an effective groundcover and weed deterrent, as I discovered. They also make excellent container plants; I plan to use them in my hanging baskets. Plants mature in about 60 days.