With our average last frost date of May 10 or so it’s time to start planting the main garden. Corn and beans can go in, and over the next few weeks, so can summer staples such as tomatoes, squash and okra.
I would not rush to plant these latter plants — wait until the soil is good and warm. The tomatoes will sit and sulk otherwise, plus you’ll get poor germination of seeds planted too early.
One item that is plentiful in my garden now but will soon be a sweet spring memory is lettuce. As soon as the weather consistently grows warm lettuce will grow bitter and then bolt. There are things you can do to tide yourself over until cooler, lettuce-growing weather arrives again, however:
• You can place shade cloth over the lettuce bed, keep the lettuce cut back to prevent bolting and water two or three times a day. Field studies have shown that it’s not just heat that causes bolting — cumulative light levels and low moisture contribute as well.
This seems as good a place as any to define what I mean by bolting. This is simply a natural process of a plant going to bloom in an effort to produce seed to propagate itself. Lettuce, and spinach for that matter, is notorious for prematurely bolting. Lettuce has compounds that cause that distinctive and unpleasant bitter taste via substances called sesquiterpene lactones. The bitterness becomes increasingly pronounced during the growing season. You can minimize the taste by washing the lettuce in warm water.
• You can plant a lettuce selected for slow bolting qualities. My favorite is a loose leaf aptly named Slobolt. Some gardeners enjoy a French Batavian called Sierra, also genetically selected for being slow to bolt. You can find these varieties easily through various seed catalogue companies.
• You can plant a hot-weather “lettuce” mix. When I was a market gardener, I grew a mix that sold like gangbusters once the main lettuce crops had bolted. These I grew as cut-and-come-again crops. I’d seed heavily and then use scissors to shear the plants when they reached several inches in height. The plants would re-grow and I’d repeat the process. You might consider placing an insect barrier over the beds as well; this will eliminate the need to spray. What I mean by an insect barrier is that you use a manufactured lightweight fabric, also available from numerous seed catalogue companies, over your crops. Insect barrier is light enough that it can rest directly on the plants, but if you prefer you can use metal hoops to keep them up and off of them. I use 11-guage lengths of wire available from the fencing section of local feed and seed stores and cut them into four-foot hoops.
My beds were about 30-inches wide and seeded with a generous hand as noted already. The 30-inch width worked well because I could easily straddle the beds and harvest.
The mixes you can plant vary widely. I generally used baby collards, arugula, baby chard, baby kale and beet greens. I’d replant a new bed every three weeks or so trying to keep ahead of the competition from weeds. Other people also have grown kommatsuna (an Asian green), vitamin green, Tokyo bekana, cutting celery and tetragonia.
Do not make the mistake I made one year and seed them all together. My thought was to mix in the field so I would not have to mix later, but this didn’t work well because the plants grow at wildly different rates. Arugula, for instance, grows very fast indeed whereas the beets grow more slowly. It’s nice to keep them separate so you can harvest according to the growth rate of a given plant.
One nifty idea that I read online in a gardening forum which I might get around to doing this year: A fellow who was selling a variation of this mix (which can be cooked or eaten raw) grew his on salad “tables” made of rows of side-by-side hay bales with three inches of mushroom compost piled on top. The tables are weed free and, over time, compost themselves and can be used to regenerate the garden. He noted that it’s important to use hay bales that are bound with synthetic twine to keep them from breaking apart prematurely. For those of us without a lot of space, or who don’t want to engage in a losing battle with weeds, this sounds like a terrific way to grow plenty of green stuff.