By Ben Penner, Farm Director
Outdoor farm work started early this year. Despite this spate of cooler temperatures over the last few days, farmers from around the state have been antsy since at least early March. They’re not alone; much warmer than normal temperatures have me thinking that I might have missed the window to plant my early season crops.
This is the first year where we have experimented with season extension, and it’s hard to know what to plant. Indoor temperatures have already surpassed the 110 degree mark — too warm for cool season crops — but with overnight lows dipping to the high 20s, it is still too cool for tomatoes and peppers. I have experimented with a few tomatoes in the tunnel for the past few weeks and they were doing fine until it got down to 25. We had built a low tunnel within the high tunnel — essentially creating a double layer of plastic — which certainly increased the temperature a degree or two, but the low temperatures were still too much. I am happy to say, however, that the lettuce we planted last fall is doing fine, and I just delivered our first official harvest to Open Arms on Tuesday, April 10.
Over the next few days, I’ll continue to experiment with other methods to add another degree or two right at the soil surface near vulnerable plants. The only drawback is that, with this extra protection, daytime temperatures underneath that second layer of plastic have reached over 120 degrees. Since the conditions have been so variable, I have been compromising by direct-seeding turnips, broccoli, kale arugula and spinach crops outside and covering them with a plastic layer or row cover, or even just leaving them bare. One way or another one of these strategies is bound to give us an earlier than usual harvest in the hot spring of 2012.
If you would like to learn more about season extension, join me to plant, weed, prune, build trellises and lay down irrigation in the hoop house and the low tunnels at Open Farms this growing season.