Real spinach - as distinct from "perpetual" spinach - does best in cool conditions. Because it bolts away in heat, I usually stop sowing at the end of May, then try another crop in August for autumn picking. If you sow in September or October, the spinach will overwinter and be ready to eat by April.
Real spinach, Spinachia oleracea, is an annual, a native of the western Himalayas that reached England only in the 16th century. Hybridisers ever since have been trying to marry the best qualities of two types of annual spinach: prickly-seeded types, which have narrow leaves but are not so prone to "bolt", and smooth-seeded types that have much bigger, lusher leaves, but can't take heat.
New Zealand spinach, Tetragonia tetragonioides, is a different animal altogether, native to the Pacific. These are the greens that the intrepid 18th-century voyager Captain Cook collected by the boatload in New Zealand to stop his soldiers getting scurvy. I think the taste of proper spinach is better. Nevertheless, I have sown the New Zealand kind (Suffolk Herbs, 75p); it stands the heat well and plugs the summer spinach gap.
Perhaps more spinach is now eaten raw than cooked, with the baby leaves tossed in salads or used like watercress in sandwiches. That's wasteful of the crop, but delicious. Used like this, you need lots of other saladings to go with it: lettuces of all kinds, chicories, radicchio, rocket, lamb's lettuce. Last year's chicory is just running up to seed in our garden. The flowers are a lovely sky blue, but they'll have to go. They get in the way of the pattern-making that is my present obsession in the vegetable garden.
It started in a smallish way when I drew a series of big X-shapes along the bottom border, dividing it up into a regular pattern of diamonds and triangles. All the diamonds are now planted with tomatoes, and the triangles are each filled with a different salad crop. By next year I hope to have completed planting the low, evergreen germander hedges that will give the border structure in winter.
It's become my favourite bit of the garden, and it is one of the prettiest just now, with the purple globes of giant chives mixed with the deep red flowers of dianthus `Hidcote' and the blue flower spires of a grey-leaved Balkan sage in one triangle, contrasting with the ludicrously glossy, crinkled leaves of a red picking-lettuce, `Redina' (Marshalls, pounds 1.25) in another. As with the spinach, you can pick the leaves of loose lettuces such as this one from the seedling stage onwards.
In the next triangle is a crisp iceberg lettuce, `Nevada' (Marshalls, pounds 1.80), a bright green against the marigolds in the neighbouring patch. You can't call marigold a salad crop, but the petals look good scattered on salad leaves.
Rocket, radish, coriander, parsley and the endive `Sally' (Marshalls, pounds 1.09) live in other triangles. I've only just sown the endive, which doesn't prosper if it goes in before May. You sow it just like lettuce, then thin out the plants to at least 1ft apart. They make flat mops, tight- hearted, stronger-tasting than lettuce. You can blanch them by covering each heart with a saucer. The advantage of endive is that, sown in succession between now and August, it will keep you in saladings till Christmas.
Successional sowing ... it seems such a comforting thought: an endless conveyor-belt of vegetables in perfect condition, each crop neatly dovetailing with the next. You can, in principle, sow a little rocket and a soupcon of radish seed fortnightly. But whether you get that seamless succession is entirely in the lap of the gods. If the weather is hot, seed germination may be delayed, but the growth of crops above ground will be accelerated. If it is cool, your second and third sowings may come on tap while you are still content with your first.
One principle you can hang on to: the shorter time it takes a crop to come to maturity, the more successional sowings you have to make.
Once you have nipped off the terminal leaf of a rocket plant, the crop goes downhill. I sowed our first lot (Marshalls, 66p) on 6 April and was picking it six weeks later. As with spinach, you get the best crops in spring and autumn. In the heat of summer, rocket runs to seed fast. You can slow down the tendency by sowing in semi-shade, and also by keeping the patches well watered.