Updates for April 2008.
The Food Garden in April
March saw many pauses in growth: it was often wet and windy and, most unusually, was cooler than February. It is blowing another gale as I write this, with horizontal rain. Polytunnels prove their worth in such months of cold winds combined with rapidly increasing light levels, and the first photo reveals abundant growth of salad leaves. A few plants have even grown well outdoors, such as leeks and kale – the other photo here is of Red Russian kale, tasty in salad.
Gardens are about to spring back to life and there is much to do. In this brief page I touch on some of the more important jobs, and some you may already have done. Having some nice clean beds to sow and plant into is the first priority and there is still (just) time to achieve this if you did not manage it in the winter. Areas of extremely weedy soil can be mulched with cardboard and covered with compost. Less weedy ground can be cleared by hand. If you kept on top of the weeds last year, neither of these tasks will be necessary and you will now realise how doing a little extra gardening can save a HUGE amount of work later. Looking for and pulling out those grasses, chickweeds, groundsel, bittercress and so forth, before they seed everywhere, keeps soil clean and ready to easily grow more vegetables.
I am often asked ‘Where do I find enough compost for use as a surface mulch?’. Mainly I recommend green waste compost produced by local authorities or contractors, from household garden prunings, mowings etc. It is usually well broken down, clean of weed seeds and good value (perhaps £20/tonne delivered), but make sure it has been sieved through a 15mm mesh at most. You actually need no more compost for ‘no dig’ than if you are digging. Either way, vegetables require good dressings of organic matter to grow healthily.
Outdoor sowings of peas, broad beans, spinach, lettuce, carrots, beetroot, parsnip, spring onion, cabbage and calabrese are all recommended now. Potatoes and onion sets want planting, by mid month preferably. Cucumbers, melons and courgettes can be sown in a greenhouse, perhaps using a heated propagator to help germinate their seeds. In mid April it is good to sow winter squashes indoors, then in late April it is possible to start sowing french and runner beans and sweetcorn – but waiting until May is often more successful for such heat loving plants.
If April is wet and cool, slugs may graze on weak and slow-growing seedlings. This happens less if soil has been kept clean over winter than if weeds were allowed to grow and provide shelter for molluscs, whose eggs will then be hatching through early spring. Slugs are a fact of life and if you want to avoid using chemicals to control them, I recommend you think in terms of making your garden less hospitable to their presence, through a clean soil or compost surface, and by always sowing seeds in season so that they grow quickly and healthily. For instance, sowing or planting courgettes outdoors in April, when it is mostly too cool for their normal rapid growth, makes them weak and vulnerable to grazing by slugs, who are simply doing their job of clearing and digesting any weak and dying plants.
Covering early plantings with fleece can help, by allowing them to grow more strongly in a warmer and more sheltered environment. Growing plants in a greenhouse or indoor space is also a valuable way of minimising slug damage to seedlings while they are at a highly vulnerable stage.
Tomatoes are perhaps the best illustration of the virtues of indoor propagation, which gives them the extra time to grow and reach maturity through our damp, temperate summers and autumns. Ideally they will be sown by now, although there is still just time, for a slightly later crop. Basil grows more quickly and often does well from a late April sowing indoors, and can be sown until early June: later sowings of basil grow more reliably because it hates the cool nights of early spring.
As the days are grow warmer and much brighter, enjoy your plot as much as you can with some productive gardening.
For more detailed information on seasonal salads, see my features in Grow It! magazine.
For descriptions of seasonal vegetables, see my piece in April’s The Garden (RHS) magazine.
For a summary of growing ideas, see The Guardian on April 5th.