Pests, Pathogens, and Lots of Row Cover


The season’s first transplanting is cause for great joy, and for great trepidation. Moving the plants from greenhouse to field is a major milestone in the journey from seed to plate, but it introduces a host of variables the farmer can only marginally control. You can irrigate when it’s dry, but you can’t opt out of the rain. You can use row cover to keep out aerial pests, but you’re stuck with the ones below ground. Row cover provides a few degrees of frost protection, but it’s no substitute for sunshine. There comes a point, once the plants are outside, where you just have to cross your fingers and hope the weather will be kind.

In truth, we could use a little more warmth right now. We transplanted the kale, chard, and collards on April 8, catching a sunny window in between days of rain. Six days later, when I pulled back the cover for the first cultivation, many of the plants were wilted. Initially I attributed it to the cold, but once I started cultivating, the real problem became apparent. Seedcorn maggot—a pest that does its worst damage in early spring—had burrowed into the stems. Some plants had just a maggot or two, and some had none, but others had dozens. Suddenly, the entire day was reoriented towards damage control. Dan, Steve, Donna, Judy, and I spent hours crawling up and down the rows, scouting each and every plant. Wherever we found a maggot, we removed the host plant and a trowel’s worth of surrounding soil. By the end, half the kale and several dozen collard plants had been dumped into tubs, with no guarantee that the remaining plants were out of the woods. Then we debated our next step. Should we fill in the gaps with the leftover plants from the greenhouse? Should we wait a