A mainstay in salads, stir-fries and so many other dishes, spinach is a versatile and popular green. It’s also among the healthiest foods you can grow, containing iron, vitamins A and C and other important nutrients.
Here are our recommendations for growing spinach with Tower Garden.
Ideal Growing Conditions
Growing spinach is much like growing lettuce, but spinach offers a greater tolerance of cold weather. Spinach prefers full sun to partial shade, and it grows best in temperatures between 35–75˚F.
When to Plant
Spinach thrives in cooler weather—even tolerating light frosts. But it struggles in hot weather. For this reason, you should plant spinach in the cooler months of spring and fall.
Early spring: Heat and longer days trigger bolting, or the process of going to seed, thus ending the growing cycle for spinach. To allow for enough growing time in the spring, plant spinach 6 weeks before the last frost. Also consider placing spinach in partial shade to discourage bolting.
Fall: Since spinach easily bolts in the warmer, longer days of spring, fall is the best time to plant spinach. Plant after the hottest temperatures have passed, about 6 weeks before the first frost. In warmer climates (zone 8 and farther south), you can often grow spinach through winter.
Spinach also grows well indoors under grow lights. And since indoor gardening isn’t affected by seasons, you can plant any time you like.
Tower Tip: To get timing recommendations based on your location, try this planting scheduler.
Starting seeds may be the most challenging part of growing spinach. Follow these instructions to ensure the best chance of successful germination.
Use new seeds every year. Spinach seeds don’t store well, so it’s best to start with new seeds every year. Otherwise, germination rates will decline.
Start seeds in a cool environment. Spinach seeds germinate best in temperatures under 70˚F. Germination rates drop significantly in warm weather. If temperatures are too high, try starting your spinach seeds in your refrigerator.
We recommend planting about 4 seeds per rock wool cube. Spinach typically germinates within 1–2 weeks. And seedlings should be ready to transplant to your Tower Garden 2–3 weeks after sprouting.
Tower Tip: For step-by-step instructions on starting seeds and transplanting seedlings, reference page 7 of the Tower Garden Growing Guide.
Preventing Pests and Disease
Tower Garden reduces the risk of pests and plant diseases. But it's always good to be prepared! Here are a few common spinach pests and diseases:
Aphids are small insects that typically feed on young plant growth, causing it to appear puckered or deformed.
Flea beetles are small and vary in color from black to bronze to metallic gray. They feed on spinach leaves, creating small, irregular holes. Excessive feeding can cause leaves to wilt.
Leafminers live and feed between spinach leaf surfaces. The signs of leaf miners are unmistakable: winding trails throughout the leaf tissue.
Downy mildew looks like fine white cotton or frosting and often infects lower plant leaves first. It can spread rapidly and kill plants in cool conditions.
You can harvest spinach as soon as the leaves are big enough to eat. Cut the outer leaves first to encourage continued production.
Regular harvests will extend your plant’s life cycle. But if you notice signs of bolting (e.g., sudden vertical growth), harvest the entire plant to prevent the remaining leaves from becoming bitter.