Garden Detective: Cool-season crops to plant now for a fall harvest

As the end of summer approaches and we prepare to harvest the last of the tomatoes, the garden still has more to give. Cool-season crops, which you may have planted earlier this year for a late spring harvest, would struggle and/or bolt during the heat of summer. But they can be planted again now and will thrive as the weather cools.

A little preparation will go a long way toward enhancing your success and the overall health of your plants. Ready the soil by incorporating 2 cups of a complete fertilizer per 100 square feet of growing space, then topping with 2 inches of compost.

Because these plants thrive best in cool soil, cover the planting area with shade cloth or cardboard for several days, then water the soil to further cool it and improve germination just before sowing seeds or planting starts.

Here are five cool-season crops to plant now to extend your growing season.

Leaf lettuce

Seek out heat-tolerant varieties, if possible. Sow seeds directly into the garden, one-quarter-inch deep, and thin as they grow. Firm the soil gently and water lightly, keeping the soil evenly moist. Begin harvesting in 30 days.

Spinach

Loosen soil going down 12 inches to accommodate spinach’s long taproot as it grows. Space seeds one-half-inch deep and 2 inches apart and, for best results, install row covers to keep soil cool during germination. Keep soil consistently moist, and apply a nitrogen fertilizer every four weeks. Begin harvesting in 60 days.

Sugar snap or snow peas

Select varieties with 60 days or less to maturity, such as snap peas, snow peas or early bush types. Broadcast, or toss, seeds in wide rows, then cover with 2 inches of soil. Install a trellis or support, and secure plants as they grow. Don't fertilize, as too much nitrogen may stunt pods. Keep soil consistently moist. Begin harvesting in 60 days.

Kale

Sow seeds in the sunniest spot available and keep soil consistently moist, but not soggy. Apply a high-nitrogen fertilizer, following package directions for dosing and timing. Flavor improves after a light frost. Begin harvesting baby greens for use in salads in as few as 30 days; fully mature leaves, best for cooking, will be ready in 60 days.

Collard greens

Plant starts (4- to 6-week-old starter plants sold at nurseries) in full sun in well-draining, moist, fertile soil, spacing them 18 inches apart to accommodate their mature size, in rows 30 inches apart. Keep the soil moist, and apply a slow-release fertilizer every four weeks.

When harvesting, remove the bottom leaves first, moving up the plant as needed. Begin harvesting mature leaves in 60 days, or sooner for baby greens.