How to Grow Spinach from Seed (A Beginner’s Guide)
Updated: Sep 30
To grow spinach (Spinacia oleracea) from seed, sow it 1 to 2 cm deep directly outdoors in cool weather, keep the soil evenly moist, and thin plants to 10 to 15 cm apart. Seeds germinate in 7 to 14 days, baby leaves are ready in about 4 weeks and full leaves in 6 to 8. In Ireland and the UK, sow from March to May and again from August to September, avoiding midsummer when spinach quickly bolts.
Spinach loves Ireland’s cool, damp climate and is one of the most nutritious greens you can grow. This guide covers varieties, sowing, care, harvesting, and how to stop it running to seed.
Spinach Quick Facts
Latin name: Spinacia oleracea
Sowing depth: 1 to 2 cm
Germination temperature: 7 to 20°C (poor above 25°C)
Germination time: 7 to 14 days
Sow (Ireland/UK): March to May, and August to September
Harvest: Baby leaves ~4 weeks; full leaves 6 to 8 weeks
Spacing: 10 to 15 cm
Position: Sun in spring and autumn; light shade in summer
Soil: Moist, fertile, rich in compost, pH 6.5 to 7.5
Step 1: Choose Your Spinach Variety
Savoy: crinkled, dark leaves with good cold tolerance, ideal for autumn and overwintering.
Semi-savoy: slightly crinkled, easier to wash, with good bolt resistance.
Smooth-leaf: flat leaves, quick to grow and easy to clean, great for baby leaf salads.
For Irish gardens, look for varieties described as bolt-resistant for spring sowings and cold-hardy for autumn sowings.
Step 2: Sow the Seeds
Direct sowing (best)
Prepare fine, moist soil enriched with compost.
Sow seeds 1 to 2 cm deep in rows 30 cm apart, or scatter thinly in blocks for baby leaves.
Water well and keep the soil moist until seedlings appear in 7 to 14 days.
Starting in modules
Sow two seeds per module in seed compost and thin to the strongest.
Keep cool (10 to 18°C). Spinach germinates poorly in a warm house.
Harden off and plant out when seedlings have 2 to 3 true leaves; spinach dislikes root disturbance, so handle gently.
Step 3: Thin the Seedlings
Thin seedlings to 10 to 15 cm apart once they have a couple of true leaves, and eat the thinnings as micro greens. For baby leaf crops, 5 cm spacing is fine.
Step 4: Water, Feed and Protect
Water: keep the soil evenly moist. Dry soil is the main trigger for bolting.
Feed: spinach is hungry for nitrogen. Start with plenty of compost, and water with diluted comfrey or nettle feed if leaves pale.
Shade: give afternoon shade in warm spells.
Pests: protect young plants from slugs and birds; fleece or mesh helps.
Step 5: Harvest
Cut-and-come-again: pick the outer leaves and let the centre keep producing.
Baby leaves: cut whole plants 3 cm above soil at about 4 weeks; they often regrow.
Whole plants: harvest the whole plant as soon as you see a flower stem forming, before leaves turn bitter.
Step 6: Keep Spinach Coming
Succession sow: sow short rows every 3 to 4 weeks in spring and again in late summer.
Overwinter: sow hardy varieties in late August and September for pickings through winter and early spring, ideally under cloches or in a polytunnel.
Skip midsummer: long days and heat make spinach bolt, so grow chard or perennial greens instead in June and July.
Troubleshooting Spinach
Bolting (running to seed): caused by heat, long days and dry soil. Sow in spring or late summer, water well and choose bolt-resistant varieties.
Poor germination: soil too warm or dry. Sow in cooler weather and keep the soil moist.
Yellow leaves: usually a lack of nitrogen. Mulch with compost and feed.
Holes in leaves: slugs, snails or leaf miners. Check plants regularly and remove damaged leaves.
Downy mildew: yellow patches with grey fuzz underneath. Improve spacing and airflow.
FAQ: Growing Spinach
When should I sow spinach in Ireland?
Sow spinach outdoors from March to May for early summer crops, and again from August to September for autumn and overwintering crops. Avoid sowing in midsummer, when heat and long days make it bolt.
Why does my spinach keep bolting?
Spinach bolts (flowers and turns bitter) in response to long days, warm temperatures and dry soil. Sow in spring or late summer, keep the soil moist, give some shade and choose bolt-resistant varieties.
How long does spinach take to grow from seed?
Spinach germinates in 7 to 14 days. Baby leaves are ready in about 4 weeks and full-size leaves in 6 to 8 weeks.
Can spinach grow in shade?
Yes. Spinach tolerates partial shade well and actually benefits from afternoon shade in warmer months, which slows bolting.
Is there a perennial spinach?
True spinach is an annual, but perennial leafy greens such as sea beet, perennial kale and Good King Henry give spinach-like leaves year after year without resowing. Perpetual spinach, a type of leaf beet, crops for over a year from one sowing.
No Bolting, No Resowing: Perennial Alternatives to Spinach
Spinach is fast and delicious, but it needs regular resowing and runs to seed in summer. If you want spinach-like leaves that just keep coming back, try these perennials:
Sea beet: the wild ancestor of beetroot and chard, native to Irish coasts. Its glossy leaves cook just like spinach and it crops for years. Available as sea beet plants or seeds.
Perennial kale: tender young leaves steam and stir-fry like spinach, and plants crop through winter for several years. See our Taunton Deane perennial kale.
Sorrel: lemony leaves from very early spring, lovely wilted or in soups. Grow it from our French sorrel seeds.
Good King Henry: a traditional Irish and British pot-herb with spinach-flavoured leaves in spring and tender shoots you can cook like asparagus. Hardy, shade tolerant and long-lived. See our Good King Henry plants.
Perpetual spinach: not a true perennial, but a leaf beet that crops for over a year from one sowing and rarely bolts. See our perpetual spinach.
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