How to grow spinach
Overview
Spinach (Spinacia oleracea) is a fast-growing leafy vegetable grown for regular harvesting of tender leaves. It thrives in cool conditions and is a staple for autumn, winter, and spring gardens. The key to success is timing—plant so leaves mature before temperatures exceed 25°C to avoid bolting.
Varieties
- Bloomsdale — A classic savoy-type spinach with crinkled leaves and excellent cold tolerance, ideal for cool climates.
- Baby's Leaf — A smooth-leaf variety bred for baby leaf production with fast growth and bolt resistance.
- Viroflay — A large, smooth-leafed French heirloom with high yields, suited to spring and autumn crops.
Soil Preparation
Spinach prefers fertile, well-drained soil rich in organic matter with a pH between 6.0 and 7.5. Before planting, dig in well-rotted compost or aged manure. Avoid heavy clay soils that stay wet, which can cause root rot.
Growing Guide
Sow seeds directly 1–2 cm deep in well-prepared soil, spacing 10–15 cm apart in rows 30 cm apart. Choose a position with morning sun and afternoon shade in warmer months. Keep soil consistently moist but not waterlogged. For a continuous supply, sow small batches every 2–3 weeks. Mulch around plants to keep roots cool and reduce moisture loss.
Sowing
Sow seeds 1–2 cm deep, directly into the garden bed, spacing 2–3 cm apart and thinning to 10–15 cm later. Seeds germinate in 5–10 days at soil temperatures of 10–20°C. Soaking seeds for 24 hours can improve germination rates.
Care
Apply a balanced liquid fertiliser every 2–3 weeks to maintain rapid, tender growth. Remove any flower stalks as soon as they appear to delay bolting. Keep the bed well-mulched to suppress weeds and retain soil moisture.
Companion Planting
Spinach grows well with strawberries, peas, brassicas, and onions. Avoid planting near potatoes or fennel, which can compete or inhibit growth.
Common Pests & Risks
Aphids and leaf miners are common. Monitor undersides of leaves and treat with a strong spray of water or insecticidal soap. Leaf miner damage appears as winding tunnels; remove affected leaves and use floating row covers to prevent egg-laying.
Harvesting
Start harvesting outer leaves when plants have at least 6–8 true leaves, usually 6–8 weeks after sowing. Pick the largest leaves from the outside, leaving the inner rosette to continue growing. Regular harvesting encourages more leaf production.
In the Kitchen
Harvest leaves can be stored in a sealed bag in the fridge for up to a week. Spinach is delicious raw in salads, or quickly wilted in stir-fries, pastas, and quiches. Wash just before use and avoid overcooking to preserve texture and nutrients.
Troubleshooting
Yellowing leaves: typically nitrogen deficiency or overwatering; feed with balanced fertiliser and ensure good drainage. Early bolting: caused by heat or drought stress; plant in cool season and keep consistently moist. Leaf miner tunnels: remove affected leaves and use insect netting. Stunted growth: often due to poor soil or insufficient light; improve soil fertility and ensure at least 4–6 hours of sun.