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Spinach

A cool-season crop that gives you iron-rich leaves in the months when the beds are otherwise bare.

1. Sow 1.5 to 2 cm deep into soil enriched with compost, in rows 30 cm apart.
2. Sow in late summer and early autumn for the easiest crop, since autumn and winter suit it best.
3. Thin to 7 cm for cutting leaves, or 15 cm for full plants.
4. Keep the bed damp constantly, watering in the morning.
5. Start picking outer leaves once the plant has six or seven leaves.
6. Cut whole plants 3 cm above the crown for cut-and-come-again, and expect two or three regrowths.
7. Pull the row as soon as a flower stem appears and sow again.
8. In cold zones cover autumn sowings with fleece or a cloche for winter and spring picking.

Soil

Rich, moisture-retentive soil at pH 6.5 to 7.5 with plenty of compost. It is a hungry leafy crop.

Sun

Full sun in cool months, part shade once temperatures climb. In Mediterranean summers it bolts within days, so do not try.

Water

Generous and constant, about 20 litres per square metre per week. Any dry check sends it straight to seed.

Spacing

Thin to 15 cm apart for full plants, 7 cm for baby leaf, rows 30 cm apart

Depth

1.5 to 2 cm deep

Care

['Feed with a nitrogen-rich liquid feed every two or three weeks, since leaf crops are hungry.', 'Never let it dry out, not even for a day in warm weather.', 'Pick regularly, because a plant left alone bolts sooner than one being harvested.', 'Slug patrol in the first three weeks, particularly in autumn.', 'In hot climates use New Zealand spinach or chard as a summer stand-in, since true spinach will not cope.']

Harvesting

Take outer leaves from the outside in, leaving at least half the plant standing, and it keeps producing for six to eight weeks. Pick in the morning when the leaves are firm. Once a central flower stalk starts rising, harvest everything at once because the leaves turn bitter quickly.

Storing

Keeps about five days washed and dried in a box in the fridge. It wilts to almost nothing when cooked, so the practical way to store a glut is to blanch for one minute, squeeze hard, portion into balls and freeze. Frozen spinach keeps six months and is fine in cooked dishes.

Grow it next to

Good with strawberries, brassicas, peas, beans and radish, and happy growing in the light shade of taller crops. Avoid crowding it against beetroot and chard, which share leaf miner.

Problems

[{'cause': 'Bolting from heat, long days or dry soil', 'fix': 'Grow spring and autumn only in hot climates, keep the soil damp, and use bolt-resistant varieties. Pull bolted plants and resow when it cools.', 'symptom': 'A flower stalk rises and the leaves go small, pointed and bitter'}, {'cause': 'Downy mildew, common in damp crowded autumn beds', 'fix': 'Thin properly, water at the base in the morning, remove infected leaves, and choose mildew-resistant varieties next time.', 'symptom': 'Yellow patches on top of the leaves with grey-purple mould underneath'}, {'cause': 'Leaf miner larvae, the same pest as on beetroot', 'fix': 'Pick and bin affected leaves, and cover the row with fine mesh. The rest of the plant is still perfectly edible.', 'symptom': 'Pale winding tunnels inside the leaves'}, {'cause': 'Not enough nitrogen, or soil that is too acid', 'fix': 'Feed with a nitrogen-rich liquid feed, add compost, and lime if a test shows below pH 6.5.', 'symptom': 'Pale yellowish leaves and very slow growth'}, {'cause': 'Slugs, especially in damp autumn conditions', 'fix': 'Water in the morning, clear debris, patrol after dark for the first two weeks, and transplant larger modules instead of direct sowing.', 'symptom': 'Seedlings eaten off at soil level overnight'}]

Saving your own seed

Spinach is wind pollinated and has separate male and female plants, so you need at least ten plants and 800 m of isolation from other spinach. Let the females set seed, then strip the dry seed from the stems. Seed keeps three to four years.

Containers

Good in a 20 cm deep trough for baby leaf, cut with scissors. Full-size plants need a 25 cm deep container and a lot more watering, so baby leaf is the better pot crop.