🥬 Spinach

Spinacia oleracea
A cool-weather diva that bolts at the first sign of warmth — treat it like the spring fling it is.
Sun
Full sun in cool weather; afternoon shade extends the season as it warms
Days to harvest
40–50 days from seed (baby leaf in 25–30)
Spacing
2–3 inches apart; thin to 4–6 inches for full-size leaves
Soil pH
6.0–7.5 (one of the more pH-tolerant greens)

How to grow

Spinach is the plant equivalent of someone who only functions between 60 and 70 degrees and has strong opinions about it. Sow directly a half inch deep as soon as soil can be worked — it germinates in soil as cold as 35°F. In the South, spinach is strictly a fall-through-winter crop; a Florida 'spring' sowing bolts before you finish reading the seed packet.

The bolting trigger is a combination of day length and heat, and once the flower stalk appears, the leaves turn bitter — there's no reversing it, only mourning it. Succession-sow every two weeks, use bolt-resistant varieties ('Space', 'Tyee', 'Olympia') for shoulder seasons, and give afternoon shade to buy an extra week or two.

Spinach is a heavy feeder for a leafy green, and it shows deficiencies fast: yellowing older leaves means it wants nitrogen. The leaves also accumulate oxalic acid, which is why overcooked spinach tastes metallic and why people with certain kidney issues are told to moderate it — normal culinary amounts are completely fine.

Water & feeding

Consistent moisture, about 1–1.5 inches a week — drought stress triggers premature bolting. Mulch to keep soil cool. A side-dress of worm castings or a gentle nitrogen source 3 weeks after germination keeps leaves deep green and growing fast.

Common problems

  • Bolting: heat + long days; sow at the right time, use resistant varieties, harvest promptly.
  • Downy mildew (yellow spots with fuzzy purple-gray undersides): water at soil level, space for airflow, choose resistant varieties.
  • Leaf miners (wiggly white trails in leaves): row cover prevents the flies from laying eggs; pick off affected leaves.
  • Poor germination in warm soil: pre-chill seeds in the fridge for a week, or wait for soil below 70°F.

Harvest

Cut outer leaves when 3–4 inches long for continuous harvest, or cut the whole plant at the base for a single harvest. Morning harvest = crispest leaves. Eat the thinnings; they're the cook's tax.

Nerdy fact: The famous 'spinach has tons of iron' claim came from a misplaced decimal point in 1870 — German chemist Erich von Wolf recorded 35mg instead of 3.5mg per 100g, and the error survived in textbooks for decades. Popeye's muscles were built on a typo.

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