Growing your own food is a complete antidote to the seasonal uniformity of supermarket shelves. Out in the garden there are still four seasons, and it is vital to understand how they affect our sowing, planting and harvesting.
Sowing at the right time for healthy plants
Confusing signals abound, from nurseries offering plants out of season, to seed packets advising unnaturally long sowing seasons, presumably in the hope that we use up more seed. What we really need is information about when is the best time to sow for the plant to achieve its full potential and grow most healthily. I have in front of me a packet of rocket seed that says on the back ‘Sow April–September’. Presumably they mean that their rocket seed will grow into nice rocket leaves at any time from late spring to early winter, but this is simply not true.
Like all plants, the growth of rocket is governed by changing day length. Days growing longer, from midwinter to midsummer, make it want to reproduce, so its energy goes into producing a stem with nice flowers that will turn into seeds as the plant dies off (see Plate 39); whereas days growing shorter, after the 21 June solstice, but more especially after about early September, send it a signal to take it easy a bit! There is time to make plenty of leaves and roots in preparation for that great seeding season in the spring … and plenty of leaves for the gardener to pick in the meanwhile.
As an organic gardener, it is vital to appreciate this calendar of activity that affects the behaviour of everything we sow; also, sowing out of season often results in plants succumbing to more pests and diseases. Consider rocket again: it is a member of the Cruciferae, also called brassicas or the cabbage family, all of which are affected by flea beetles making lots of little holes in their leaves, but chiefly from mid-spring to late summer. So even if you do achieve some rocket leaves in May and June, they are likely to be peppered with these beetle holes that enlarge as the leaves grow bigger, whereas an August sowing will produce cleaner leaves in the autumn and winter, when flea beetles are much less active.
There is a major link between sowings made at the right time and healthier growth. Spring salad sowing should be lettuce above all, as it grows most healthily then and is not in a rush to make seed until later in the summer. Furthermore, frequent and careful picking of its leaves will delay the seeding attempt by at least a month (see Chapter 9). In contrast to lettuce, all the oriental greens have an internal clock that is similar to rocket, so it really is not a good idea to sow mizuna or pak choi in the spring. Your leaf harvest will be quite small, and they will be of relatively poor quality. Sow them in July and August.
As a rule the most discouragement stems from sowing too early, before conditions are right or the soil is warm enough for plants to flourish. Until you have some experience, err on the side of caution. In my first year of learning to grow vegetables I sowed carrots in January, as recommended on the back of the seed packet. I never saw any seedlings, although they probably came up briefly before slugs ate them off – a complete waste of time and seed. Now I make the earliest carrot sowing in late March and even then, if the weather turns wet, allowing slugs to prosper and eat the baby carrots’ leaves, it can be necessary to re-sow.
Bringing the ‘right time’ forward
Carrots (except for round ones) and parsnips are difficult to raise as greenhouse plants, but I sow almost all other seeds in my greenhouse, into modules or seed trays. They grow into vigorous plants that can resist slugs and give an earlier harvest. Spinach in April, beetroot in May and courgettes in June are most satisfying to harvest, at a time called the ‘hungry gap’ because few other crops are ready. Look at Chapter 6 for some ideas on both how to grow your own plants and how to extend the season a little with such simple materials as a roll of fleece.
Weather and climate
Plants grow and mature quite differently from one season to the next. One year my onions keep brilliantly; the next I lose half to a fungus that arrives in midsummer. Potatoes can be blight-free one autumn and full of it the next; leeks and celeriac may struggle through a dry summer or flourish in a wet one. I strongly encourage you to learn the basics of what conditions each plant likes, so that you can adapt your growing to their different requirements, but there will always be the unforeseeable consequences of extra rain or sun.
Over the last three decades I have experienced a range of vastly different years, and have also recorded an interesting rise in temperature that has extended the growing season by about a week at either end. For example, sweetcorn used to occupy ground for almost the whole growing season, whereas, for now at least, it matures early enough for significant crops of late salads to grow in the same bed through autumn.
But there is still no certainty as to whether next spring will be cool and damp or warm and dry. What works one year may fail the next; all we know for sure is the seasonal requirements of different plants, with experience giving a glimpse of the timings and methods that have most chance of success. I invite you to benefit from my years of trying different things to learn how sowing at the right time is an invaluable but oft-ignored part of successful growing, and even helps in dealing with slugs and snails.