Succession interplanting allows you to double the output of each of your garden beds by pairing up plants that will grow together in close quarters without interfering with each other and then following with a full second crop for fall and winter. It is possible to get as many as four crops per bed in a single growing season. You won’t end up with nice rows of identical plants like you see in magazines, but the esthetic loss is diversity’s gain and it’s not so hard on your soil.
There are no tomatoes in this plan. Grow them in a separate bed with plenty of space around them. Some plants can’t be crowded and few plants are more likely to disappoint when things don’t go their way than tomatoes.
Bed One: Radish, Carrot, Leeks, Broccoli or Cauliflower, Lettuce
Sow radishes and carrots in early spring alternating seeds about an inch apart in rows about six inches apart, about half the normal row spacing. Plant leeks in the spaces between the rows to repel carrot rust fly. The radishes will mature and be gone within five weeks, about the time that slower-growing carrots begin to bulk up. Radishes take little in the way of nutrients from the soil and the carrots will really benefit from the extra space.
When you harvest the baby carrots around the end of June/early July alternate three- to four-week-old broccoli or cauliflower and romaine lettuce seedlings 12 inches apart. Broccoli and cauliflower have deep roots that don’t compete with shallow roots of the lettuce and the shade from the large fast-growing broccoli leaves keeps the soil cool and moist, which lettuces love.
Bed Two: Peas, Spinach, Zucchini, Arugula
Alternate peas and spinach seeds about two inches apart. The peas will grow faster and provide shade, which spinach likes. Peas also collect nitrogen from the atmosphere and store it in the soil, which spinach also likes.
When the peas form pods start your zucchini seeds indoors. Around the end of June harvest the last of the spinach and cut the pea vines off at the soil, leaving the roots in place. Plant the zucchini seedlings on hills about three feet apart and sprinkle arugula seeds in the low areas between the hills, covering them lightly. The shade from the zucchini leaves will help the cool-weather arugula thrive and the nitrogen from the decomposing pea roots will satisfy arugula’s nitrogen hunger. You can plant more arugula or spinach when the zucchini vines come out in September and have leafy greens through to December.
Bed Three: Mescluns, Chard, Napa cabbage, Collards
Sow mesclun greens such as mizuna, corn salad and radicchio in early spring. You can just sprinkle the seeds around the bed.
As you harvest greens in May, plant chard seeds directly into the spaces you create. By June the greens will have run their course and you can plant napa cabbage into the remaining spaces. The chard will mature in mid-July, allowing you to plant collard greens as each space comes free until about mid-August. The napa cabbage will mature around the end of September, leaving space for the expanding wingspan of the collards. Harvest collard leaves from the bottom of the plant throughout the winter.
Note: You can substitute green beans for the broccoli in bed one or the napa cabbage in bed three. Cut the bean vines off at the ground to leave the roots in place.
( adapted from Randy Shore: The Green Man Blog Vancouver Sun, March 11, 2012 )