How To Quick Plant and Grow Spinach

It’s easy to understand why organically grown spinach is so popular. This delicious, highly nutritious leafy vegetable is not only easy to grow, but actually thrives where temperatures fall too low for most other vegetables.

Spinach does best in cool soil. In fact, the seeds are difficult to germinate where soil temperatures remain above 20°C. In short, this is a perfect cool climate food plant because harvesting can take place from late autumn through winter, and with successive sowings can continue into spring and early summer. The best sowing times are during autumn and winter after the soil has cooled to somewhere between 8°–15°C.

In the past, a major problem when growing spinach was its tendency to bolt to seed rapidly, even in cool conditions Consequently, leaf harvesting was limited to a few weeks in early spring. However, modern breeders have now produced varieties that are not only bolt-resistant, but have larger and thicker leaves. These are the main spinach varieties now commonly available in Australia.

Good ones to try include ‘Winter Queen’ (big, thick, crinkled leaves), ‘Viking’ (smooth, easily washed leaves), ‘Bloomsdale’ (slow to bolt) and ‘Catalina’ (spear-shaped, tender leaves).

Soil Preparation

Choose a well-drained bed in full sun or light shade. Good soil preparation is essential. This means cultivating and raking the ground to remove weeds, especially perennials. Spinach plants detest acidic soils, so be prepared to add lime where necessary. Incorporating wood ash or mushroom compost will also make the soil more alkaline. Finally, work in plenty of organic matter to create an ideal environment for growing spinach.

Last year I used homemade biochar with incredible results. It was just a simple mixture of half a bucket of pulverised charcoal plus half a cup each of fish emulsion and seaweed concentrate. Two litres of water were added to create a black slurry. This nitrogen-enriched biochar was worked thoroughly into the soil for steady, slow release.

If you don’t make your own biochar, you can purchase it and still add nutrients such as fish emulsion, seaweed, worm juice or liquid compost to make your own nutrient-rich slurry. Where poorly drained conditions develop in winter, be sure to create long, raised sowing ridges in the soil. They provide the perfect drainage demanded by spinach plants.

Spacing : 30cm (15cm for baby plants)

Position : Full sun / Semi-shade

Sow seeds :
- Cold temperate : March to June
- Warm temperate – subtropical : April to July

Sowing From Seed

Unless there is no alternative, resist purchasing those tempting punnets of leafy seedlings offered for sale at garden centres. Unfortunately these plants can be a waste of money, time and garden space. This is because even tiny spinach seedlings develop long, fragile roots, making them vulnerable to transplant shock. This is why punnet-grown seedlings often bolt wastefully to seed after producing just a few edible leaves.

For successful crops, spinach seeds are best sown directly into the garden where, after germination, the seedlings continue to grow and mature without disturbance. Sow the prickly seeds 1cm deep along the crest of each ridge and backfill to cover. Then gently water again to start the germination process.

The tiny seedlings emerge about 10-15 days later and are usually overcrowded. Thin so those left to grow on are about 30cm apart. If intending to harvest entire plants earlier for baby spinach, the seedlings can be grown more closely – about half that distance.

During growth, sprinkle seedlings with well-diluted, high-nitrogen liquid fertiliser, preferably fish emulsion. I keep a watering can brim-full with a couple of tablespoons of emulsion added. This weak mixture is watered not over but around the developing plants every week.

Spinach can also be grown in large, deep pots or troughs using high-quality potting soil. A 50cm-wide container can grow up to five plants, enough to supply plenty of leaves for many weeks.

Greenhouses and plastic tunnels are unsuitable for growing spinach, mainly because the extra warmth initiates early bolting. Although spinach leaves are soft and tender, they are remarkably frost-resistant. Heavy night frosts can freeze entire plants solid, but because the chilling takes place relatively slowly, there is rarely any damage and growth continues after each daytime thaw.

Harvesting

Harvesting begins when outer leaves are big enough to be plucked. This encourages more leaf production. The best time to harvest is early in the day when leaves are fully engorged with moisture, so taste better. Always wash before eating. Spinach leaves are more nutritious when eaten raw or lightly steamed to a wilting stage. Boiling destroys much of the food value.

In cool and temperate districts, harvesting from plants started in early autumn can begin from around midwinter and continue until mid-spring. That’s when rising temperatures cause plants to bolt. Even then, plants starting to flower can be cut back hard to produce a few bonus leaves before they bolt again.

Spinach Alternatives For Warmer Climates

Ceylon or Malabar spinach (Basella species) : A vigorous climbing plant that can be sown all year in the tropics, but in spring or summer in cooler regions. The leaves are eaten raw or cooked and are high in vitamins and minerals. Red- and green-leafed forms can be grown.

Egyptian spinach (Corchorus olitorius) : Also known as molokhia. A fast-growing annual, it is high in protein as well as vitamins and can be eaten fresh or cooked. Seeds are usually sown in spring, but in the tropics can be sown all year.

Water spinach (Ipomea aquatica) or Kangkong : Needs to be grown in water or in very damp soil. Young leaves and growing tips are tender and crunchy and are usually cooked. Seeds are usually sown in spring.

Lagos spinach (Celosia argentea var. argentea) : A common edible plant of Africa, Central America and Asia. Young leaves, shoots and flower buds make a nutritious green vegetable. Plants grow easily from seed and can become weedy.