Spinach: The Cool-Season Green That Bolts in Heat
Spinach is a cool-season leafy green that matures in 40–50 days. It bolts (goes to seed) above 75°F, so plant it in spring or fall.
Spinach is easy to grow but unforgiving in heat. Time it right and you’ll harvest for 6-8 weeks.
Quick Facts
| Attribute | Value |
|---|---|
| Days to sprout | 7-14 |
| Days to harvest | 40-50 |
| Sun | 4-6 hours |
| Spacing | 4-6 inches |
| Bolt temp | Above 75°F |
| Flavor | Mild, earthy |
Why Grow It
- Fast. 40-50 days from seed to harvest.
- Nutrient-dense. High in iron, calcium, vitamins.
- Cut-and-come-again. Harvest outer leaves, plant keeps producing.
- Frost-tolerant. Light frost makes it sweeter.
How It Fails
Failure 1: Bolting. Above 75°F, spinach sends up a flower stalk. Leaves turn bitter. See: Why Your Spinach Bolted.
Failure 2: Yellow leaves. Nitrogen deficiency or overwatering.
Failure 3: Slow germination. Spinach seeds have hard coats. Soak 24 hours before planting.
Comparison
| Variety | Bolt Resistance | Flavor | Best Season |
|---|---|---|---|
| Spinach | Low | Earthy | Spring/fall |
| Kale | High | Mild, sweet | Year-round |
| Swiss Chard | High | Mild, beet-like | Spring-fall |
| Arugula | Low | Peppery | Spring/fall |
Common Questions
Why is my spinach flowering? Bolting. Too hot. Harvest immediately, replant in fall.
Can I grow spinach in summer? Only in shade. Or grow New Zealand spinach (different plant).
How do I harvest? Cut outer leaves, leave the center.
Can I grow it indoors? Yes, with 4-6 hours of light. Cool room helps.
How long does it last in the fridge? 5-7 days in a plastic bag.
Can I freeze it? Yes. Blanch 30 seconds, then freeze.