Sign up now for your FREE Newsletter. You will receive a Newsletter twice a month providing tips, techniques, and fun projects for your garden. Sign up now
Sign up now.
In a nutshell: Sow seeds in late summer and keep things cool.
The whole story: In order to overwinter, spinach needs to be about an inch high before the first hard frost, so you need to direct-seed it about 4 to 6 weeks before the cold weather hits. But here's the catch: spinach doesn't germinate well in soil that is over 70° F, a temperature that soil often reaches in late summer. What's a gardener to do? Chill out, and play this cool trick on the seeds:
Choose a variety such as 'Bloomsdale Long Standing' that is adapted to overwintering. Freeze the seeds for two days, then remove them from the freezer, sandwich them between damp paper towels, and seal them in a plastic bag. Refrigerate the seeds for five to seven days. This technique adds more than a week to your planting schedule, so start early enough for the spinach to reach its optimal prewinter height after sowing.
In the meantime, clear the bed that you plan to sow spinach in and water it well. Then cover the whole area with shade cloth. Mini hoophouse frames work well as shade-cloth supports. Shade cloth cools the soil and protects emerging seedlings from hot late-summer days. After chilling the seeds, sow them into the prepared and shaded bed. It's a good idea to sow more seed than you would in spring.
After the first few light frosts, remove the shade cloth and cover the small plants with 3 to 4 inches of straw or dry leaves; then wait. Next spring, pull off the mulch as soon as the soil is workable, and voilà—instant spinach garden. You can snack on a few tender leaves that very day, but hold off on a Popeye-worthy harvest until the plants resume active growth.
