The other day, when picking produce from my community garden, I was enthralled by a bumble bee buzzing in front of a cucumber blossom. It landed on the edge of the flower, burying its head inside. Soon it moved on to another blossom, then a third. Later, little hoverflies worked their way across a collection of white cilantro blossoms. It is the height of summer; plants have full leaves, and they are flowering. Fruits and vegetables are growing larger and ripening.
All of this verdurous growth creates a buzz in the insect world. A number of years ago, after deciding to garden organically and soaking in the wisdom of entomologists I have had the pleasure of learning from, both my tolerance of and fascination for bugs have markedly increased.
For the purposes of this discussion, I will focus on three categories of insects. First, there are the insects that eat or otherwise destroy your plants, like the cucumber beetle I recently killed. Second, there are the insects that are very helpful, the above-mentioned bumble bee and hoverfly are two examples. Finally, there are the insects that “worm” their way into our hearts because they kill harmful insects (we love these guys!).
Fostering a Healthy Insect Population
There are many things one can do to foster the symbiotic relationship that insects have with one another and with our plants. As a baseline, it is wise to take the time to search for and plant disease resistant varieties of seeds or plants. I learned my lesson this year when I planted four kinds of cucumbers. A couple are resistant to cucumber wilt bacteria and a couple (that I just HAD to try) were not. Guess what? The varieties that aren’t resistant have cucumber wilt. This is a disease that is spread by the cucumber beetle, and the bacteria overwinters in the soil. This is happening in my community garden, where the history of what was planted in years past is unknown. (I might have been given a little bit of a break if I had known where cucumbers had been and planted this year’s in a different spot.)
A great way to help the pollinator insects is to let some of your plants go to flower and then seed. The butterflies, bees, and hoverflies will love you for it! I always leave a portion of my cilantro, arugula, lettuces, bak choy, basil, mint, among others to flower and seed. Those plants are very busy places right now. In addition, I scatter flower seeds throughout my garden. Nasturtiums, marigolds, and sunflowers are all edible and thus beneficial in several ways. Then there are the blossoms on tomatoes, eggplant, cucumber, watermelon, squash, peas, beans, etc. What a plethora of options for our insect friends!
Another helpful practice is to plant things that are specific foods for certain desirable insects. I let my fennel reseed itself every year and plant dill everywhere because that is what the black swallowtail butterfly larvae eat. With Monarch butterflies, their larvae only eat milkweed, so including that in your landscape will help them multiply.
One of the more interesting groups of the insect world are the predatory insects. We all know about ladybugs eating aphids, but other examples include the cicada killer wasp as well as spiders. One of the more voracious predators, and maybe the most maligned, are spiders. Let’s just say spiders are not vegetarians. They eat other insects, many of them harmful to our yard and garden plants. So instead of cleaning up all those cobwebs in your garden, leave them. I’m not saying to leave the cobwebs around doors, windows, and house. But in your garden, these hungry critters are doing your work for you.
Think twice before you buy packages of earthworms, lady beetles, praying mantis, etc. I could write an epistle on the downsides of introducing foreign bugs into your environment. Instead, foster the conditions to help the native bugs that are already present thrive and do their thing.
It goes without saying, use insecticides either not at all or very, very sparingly. Most insecticides don’t discriminate between helpful and harmful insects.
It doesn’t take much to change your way of thinking and your practices. Just like many of us try attract birds to our yards, we can attract insects. In fact, it is easy to do this because much of what attracts insects is leaving your garden alone. Don’t harvest some of your greens, don’t apply insecticides, don’t pick all your flowers. This laid-back approach will, in the end, increase your insect population, which will increase the health of your plants and lead to higher production.