After a remarkably cool May, Memorial Day brought the first real hot weather our way. Saturday’s high was in the low 80s, Sunday it got up into the upper 80s, and Memorial Day the high temperature was over 90! That’s good weather for planting hot-weather garden denizens like tomatoes, eggplants, string beans and squash. Those vegetables like it when the soil is nice and warm and nights don’t get too cool. Unfortunately, high temps like that are bad weather for my lettuces and peas. But I’m not complaining. I can’t remember having such a mild spring in all the years I’ve lived here, so we were due for a warm spell. Plus, over the years I’ve amassed a repertoire of tricks to help my cool-weather greens hang on as long as possible.
Number one, I plant varieties that have proven to hang on well in warm weather. Green Ice is a favorite, and so are the various “oak leaf†types. Watering regularly help a lot, but even more important is providing shade for the delicate lettuces. I usually plant them on the back side of my south-facing garden plot, so that as the tomatoes and other vegetables grow higher they provide some natural shade for the greens behind them. I don’t rely solely on incidental shade, however. I set up shade covers using steel hoops and a specially designed shade cloth that I leave permanently in place once the hot weather of June arrives. Using the shade cover adds at least another two weeks to my lettuce harvest. You can find shade covers from many mail-order catalogs, and they’re re-usable over and over. I think mine originally came from Gardeners Supply, and I’ve had them at least six or seven years.
Even a shade cloth can’t get the lettuce through the whole summer, of course. Soon the greens will start to bolt. They’ll get tall and leggy, and the flavor will grow bitter as the plants prepare to bloom. If I don’t pull them out promptly they’ll eventually send up flowers and set seed. Once they show signs of bolting, I usually bow to the inevitable and take them out, replacing them with a second sowing of squash or haricot vert green beans, since they actually like the heat.
