The beautiful thing about being some of the first to have plants in the ground first is, of course, early abundance and garden joy; the downfall is that the pests also love the early growth. These past few weeks a good bit of gardening in community has meant managing pests in community, with bouts of frustration, triumph, and good lessons. This year, following the spotting of our first potato beetles, Vic Izzo, entomologist, professor, gardener, researcher and more, paid us a visit to teach us about the pests in our garden.
Before we began identifying pests, Vic introduced us to the idea of integrated pest management. Pest management methods fits, more or less, into four categories: cultural, mechanical/physical, biological, and chemical. These represent varying levels of intervention and are traditionally thought of as a hierarchy, with cultural as the least invasive and chemical as the most. Vic encouraged us to think less rigidly about the “hierarchy,” and address our unique circumstances as small scale, community gardeners by mixing and matching pest management methods.
Here are our most familiar and persistent pests, with Vic’s suggestions, as of the end of May:
Flea Beetles: Flea beetles overwinter in the soil and emerge as soon as there’s plant matter to munch on, aka our brassicas. The most common indicator that they’ve found your young brassicas is many tiny holes in the leaves of your plants. For us, this happened very quickly. Our first pest management effort was covering the plants with row cover. Larger brassicas like cabbage, broccoli, kale etc. can survive flea beetle bites once they get bigger, so we were able to use row cover while they were young. This would be considered a physical/mechanical pest control, because we created a physical barrier to keep the beetles out. Something else we’ve done to control flea beetle is spray Neem Oil, an organic, plant based oil, directly onto the plants. Sometimes row cover just isn’t enough, or it doesn’t fit over your beautifully large broccoli, or it’s causing other pests to breed around those plants (swede midge in our case), or it’s keeping beneficial insects (like pollinators and natural predators) out. We’ve taken row cover off for all of those reasons in the past few weeks. Monitoring the plants regularly, such as every time you water, is crucial at this stage to identifying the best pest management method for your unique garden.
Leaf Miner: Leaf miner most commonly, and most drastically, affect our spinach, beets, and Swiss chard. They lay white eggs on the back of the leaves and then burrow into them, eating away at the cells, leaving only their paths and the shell of the leaf. Leaf miners leave the leaves when they are adults and then they fly away to continue wreaking havoc. We typically manage, or try to manage, leaf miners by pruning off any leaves with damage (and taking them far, far away from the garden) and mushing eggs off where we see them. However, these are often persistent and very hard to manage even with that. Vic had recently heard from an entomologist colleague that they had had luck using sprays made with Spinosad, a naturally occurring bacteria, in controlling leaf miner. The spray he brought us is called Captain Jack’s Deadbug, but it is also bought in larger quantities at a different concentration under the name Monterey. This could either be considered a biological or chemical control, depending on what you consider the bacteria. Vic told us we didn’t need to panic and use it yet, but to try it out in the case of a true infestation.
The list of pests for us goes on, including three striped potato beetle on our Solanaceaes, slugs on our cabbage, and more that we are anticipating with row cover and leaf checks. If you have any unknown pests in the garden or need advice on managing them, feel free to reach out to UVM Extension’s Plant Diagnostic Clinic here. In the meantime, we harvest and enjoy each other’s company in the garden!