It has been estimated that a 10m (30ft) row of spinach supplies just about the right amount for a family of four during the summer months. But one sowing is not sufficient. Fresh young foliage is demanded and where spinach is much appreciated, successional sowings should be made fortnightly between late March and mid-July. For later autumn supplies and for pickings in the following spring, a sowing should be made in a sheltered position in mid-August.
Spinach needs a rich, well-dug soil and one which retains moisture during the summer months. For the leaves to be really succulent, the plants need soaking with water during dry spells. Some gardeners find that their plants need less water if rows sown in May, June and July are partially shaded by other, taller vegetables.
Well-rotted farmyard manure or garden compost should be used in the preparation of the bed. A suitable dressing for sandy soils is 50kg (1cwt) of manure to 6 sq m (6 sq yd). Garden compost may be used more generously. Provided the soil contains sufficient plant nutriments, no feeding of the plants is necessary. Rows of August-sown spinach are sometimes fed with nitrate of soda, applied at the rate of 28g (1 oz) to each 3m (10ft) of row, in early April.
Sow the seeds as thinly as possible in 2.5cm (1 in) deep seed drills spaced 23cm (9in) to 30cm (1 ft) apart. Thin the seedlings to 7cm (3in) as early as possible and start harvesting the leaves as soon as they are of usable size. Do not wait until they are on the tough side. Regular hard picking is essential for summer spinach and almost all of the leaves of a plant may be removed at any one time. Plants from the August sowing should not be treated in this manner. Take only the largest leaves from them.
`Round Seeded’ and ‘Long Standing’ are popular kinds for spring and early summer sowings. ‘Long Standing Prickly’ is hardier and is sown in August. The word ‘prickly’ refers to the seeds and not to the smooth leaves.
Perpetual spinach or spinach beet is less well known. Those who know it prefer it for its larger leaves. Sow in April, allowing 38cm (15in) between the rows. Thin the seedlings to 20cm (8in) apart. Successional sowings are not necessary because leaves may be pulled from the plants on and off between early summer and September.