When spring plantings are harvested, immediately replant with summer crops.
© George Weigel
Many a rookie vegetable gardener sees planting the garden as a once-and-done spring thing. The soil gets dug one fine weekend, the beds all get planted in one fell swoop, and then whatever pans out gets harvested as it’s ready. That game plan works to a degree, but it lets a lot of potential yield off the table.
Experienced veggie-meisters milk maximum return out of their soil by planting continuously as long as the weather allows. Rather than yank that early planting of, say, cabbage or broccoli, and call it quits for that space for the year, veteran gardeners know they can replant with a second summer crop that will mature before the season ends. Double- and even triple-cropping is possible for most regions of the United States. Those in the warmer parts of the South and West can plant all year long, while even northernmost gardeners can get at least two quick-maturing crops from the same space each season. Recharging the vegetable garden in summer not only gives more produce from the same space, it prevents latter-season bare spaces in the garden that only end up going to weeds anyway.
The key to conducting a season-long edible symphony is planning: knowing which crops prefer cool vs. heat, and their grow-time from planting to harvest. Popular cool weather vegetables include peas, onions, leeks, radishes, lettuce, spinach, mesclun, carrots, broccoli, cabbage, cauliflower, kohlrabi, potatoes, red beets and kale. These all grow well – and often better – in the cool temperatures of spring and fall. Cool-weather crops may become inedible in hot conditions: radishes get hot-tasting and woody; lettuce becomes bitter-tasting; broccoli fast-forwards to the flowering stage instead of filling out into large, tight heads. By planting those crops from late March through late April (even earlier in the South and West), they are ready to harvest just as punishing heat arrives.
A new summer crop of green beans is just getting started where spring-planted lettuce has been harvested.
© George Weigel
Rather than let the space lay bare after harvest, immediately replant with crops that prefer heat. These include beans, tomatoes, peppers, cucumbers, melons, squash, pumpkins, basil, corn, Malabar spinach, and sweet potatoes. A few cold-tolerant crops, including beets, carrots, and some lettuces, also grow well in summer, so long as you keep them watered. Tip: Plant lettuce on the "afternoon-shade" side of tall corn or tomatoes to take advantage of shady spots.
The best summer replacements are those that mature before the shorter days and cooler temperatures of fall signal an end to the growing season. Check the seed packs or plant labels for the average number of days between planting or sowing and harvest. These vary widely even for the same kind of plant. For example, one variety of tomato that produces large, red fruits may take 75 to 85 days to start yielding, while another variety (usually cherry types) may do the same in as little as 50 to 55 days. If your season is short, stick with fast-maturing types. Similarly, some corn can be in and out of the ground in two months; other varieties need three months.
Rule of thumb: Find out your average first killing frost date in fall, then make sure your prospective plant’s maturity time falls within the number of days between planting and killing frost. Here’s a map of spring and fall frost dates from nationwide plant grower Bonnie Plants and a searchable frost dates chart from the National Oceanic and Atmospheric Administration.
Let’s suppose you've planted a spring crop of lettuce, and by late June, it’s either been harvested, or gone bitter and been composted. Your average last killing frost date is mid-October. That means you can replant with a heat-preferring crop that matures in less than about 100 days. Many choices fit that bill, such as beans, squash (they need space), a fall crop of beets or carrots, or even with one of the faster-maturing varieties of corn or tomatoes.
The best overall yield comes from gardens that take advantage of every bit of space as soon as it can be used, then kept full until the weather makes new plantings impossible or impractical.
Lettuce is interplanted with broccoli to make the most of this garden space.
© George Weigel
To maximize production even more plant short, quick-maturing crops among the bigger ones that take longer to mature. For example, plant radishes between cabbage plants. By the time the cabbage plants are filling into the space you've allotted, 30-day radishes are up and ready to pull. Or tuck in leaf lettuce or 60-day beets between tomato plants. These crops will grow in the open spaces while the tomatoes are short, then be ready to harvest when the tomatoes get big.
By interplanting, and replanting something new whenever something comes out, veggie-garden yields can easily double or triple the norm. Even then, some gardeners extend the season by using cold frames, floating row covers and other plant-protecting measures.
Keep weeds at bay by using Preen Vegetable Garden Organic Weed Preventer to prevent weeds for up to 4 weeks. Weeds take moisture and nutrients from the soil and can choke out the plants you worked so hard to nurture. The garden will be a lot less weedy from mid-summer on, too.