Updates from December 2011.
This year has been phenomenally bountiful in my plot of undug soil, with some of the largest and healthiest vegetables I have ever grown. Many things are contributing to the wonderful growth, especially that for most gardening I do not disturb the soil at all, not even any ‘tickling’ or ‘forking’. Occasionally soil has to be moved a little, as with light hoeing of the surface, removing roots of harvested plants and when extracting long carrots and parsnips, but mostly my clay stays firmly underneath a layer of organic matter on the surface. And firm it is. This means it does not stick to boots in the way that dug soil can, can be accessed in any weather, and stays put when heavy rain washes down the slope of my gardens.
Fourteen years without digging means Lower Farm is the most mature no dig garden I have run, after ten years at the other end of Shepton Montague in the 1980s, on Cotswold Brash soil (written up by Jane Grigson in English Food), and five productive years on white clay in southern France.
Harvests from the fifth year of my dig/no dig experiment (under its own banner on the second line above) show the productivity of undug soil, and dug soil for that matter, and other benefits of no dig – see the banner Experiment.
Some still say that “soil becomes compact after x years without digging”, but I find that as long as soil organisms such as worms are fed with organic matter, the structure keeps improving and growth becomes healthier and stronger. I just harvested a 5kg Fildekraut cabbage (above!) and it is so sweet that even the teenagers are tucking in.
I like some aspects of December. Less rushing to keep up with growth, enjoying harvests of kale, brussels sprouts, parsnips and leeks, clearing beds and spreading compost. The garden suddenly looks a little bare, although this year there is already some springlike growth of broad beans and garlic. Whether this will continue is anybody’s guess but it is wise to be ready for cold weather at some point, probably in February when we are ready for some warmth!
I am about to put a cloche on some salads of spinach, scarole endive, land cress, chervil and wild rocket. A rabbit has eaten most of the last three but we have had excellent leaves off the first two, picking them hard before and then covering, which should keep rabbit out, except he will find something else to nibble…
Outdoor salad leaves
Lambs lettuce has been amazing this autumn, with near-perfect conditions for it in November: plenty of dampness in the soil surface and temperatures always between freezing and about 15C. I have found a great new variety, Pulsar from Tuckers (Rijk Zwaan seed) with compact but substantial growth. Re-growth is good too, after cutting the main leaves out of a plant and leaving two or three sideshoots below the level of cut. Plants are darker green and thicker leaved than the otherwise lovely D’Orlanda.
Land cress and winter purslane have also grown better than ever, offering several harvests already. The cress leaves are smaller each time, because of decreasing light levels, but always of excellent quality and mouth filling flavour. Rocket at this time is often turning spotty with fungal infections but the high temperatures have kept it in great health. Likewise all the mustards. If hard frosts are imminent, I shall cover these salads with fleece. Meanwhile…
Indoor salad leaves have been picked less hard, so far
An abundance of growth in the tunnels means we should have enough leaves to meet orders in December and at Christmas, helped by continuing outdoor leaves (especially scarole endive, and chicory hearts both red and white). But daylight decreasing even further means new growth is smaller and weaker with less weight in leaves. This continues into January when temperatures are often lower, offsetting the slightly increased light levels.
Ideally you have salad plants well established at this time of year, possessing a fair amount of root growth, so that any spring warmth can be quickly translated into new growth. On the other hand if seed was sown recently and seedling plants are still small, you will have longer to wait until harvests can happen.
Winter temperatures in Britain are mostly mild enough for indoor salads to survive comfortably. They tolerate freezing to about -10C for a night or two and last year my only losses were of lettuce in a poorly ventilated part of the long, sixty foot tunnel, where air struggles to reach the middle. Doors are left open at all times and in the wider, shorter (18×30 foot) tunnel, I have mesh doors at either end, so that air can flow in a gentle way, all the time. Plants, salads especially, need continual fresh air more than an extra degree or two of temperature.
Likewise in both tunnels I have some mildew on outer leaves of lettuce, but there is hardly any on leaves of the same lettuce in my smaller and highly draughty greenhouse.
In late November last year we were rushing around with nets to cover large brassicas and broad bean seedlings. This year, no damage so far, but it can change quickly if the temperature drops so either cover plants now, or be prepared with something to keep pigeons and rooks off, once you notice any damage. I wait as long as possible before covering because it is so much easier to pick kale, brussels sprouts and savoy cabbage when they are uncovered.
Just to emphasise that this is still a great time for spreading compost and composted (stacked) manure. Worms and other soil life can feed on it through winter, leading to improvements in soil structure as they move up and down to feed on it, and ingest it into stable soil aggregates.