Updates from March 2012.
Update March 14th
All photos from 12th March.
It is the usual stop start spring, some days warm and bright, others grey and cool. During the former, one gets carried away with ideas for summer sowing, but on the whole it makes most sense to stick with a good calendar of sowing. So it is still too early to sow courgettes, french beans and sweetcorn, unless you plan to grow them in a polytunnel. In which case this is the right time – preferably with some warmth in the propagating area, or on a windowsill. For growing them outdoors, wait another month before indoor sowing.
From now on you can sow spinach, carrot, lettuce, broad bean and pea outdoors, preferably in soil which has been bare all winter so that slug numbers are low. A fleece cover laid over the bed after sowing will retain any warmth and help early growth.
Seedlings of annual weeds are starting to emerge and it is worth having a hoe ready for any larger areas which can be quickly cleared of many hundred potential weeds. Keep an eye on empty beds as well as those with vegetables growing.
This should be a great month for gardening as the weather turns springlike at times. Any dry weather in March is valuable for weeding and sowing but does not mean a dry summer, as we have learnt in recent years. However, since the possibilities of a drought in parts of Britain are now being mentioned, this is a chance to remember how an undug soil is beautifully conserving of water, for two good reasons.
First, no moisture is wasted during cultivations, which expose large surface areas of soil to drying winds. Second is that the undamaged structure of no dig soil is, in my experience, good at holding on to rain that falls. This is helped by any organic matter which has been added, its sponge like qualities serving as a moisture reservoir, as well as a temperature regulator and evaporation reducer when it is on top of soil. This structure also allows passage of any excess rain so the soil regulates itself nicely, even here where there was compacted clay in part of the garden, twelve years ago.
However, moisture reserves are not unlimited and if growth happens for long enough without any new rain, soil becomes too dry for new growth and watering is necessary. Let’s hope that won’t be too common this year.
Parsnips are a beneficiary of undug soil and want to go in soon, before the surface dries out too much. I sow them into the surface mulch of manure that was spread last November, which keeps seeds moist until they germinate and then root into the firm but damp soil underneath. As they grow, worms are moving the compost and manure into soil around the parsnip roots, but not in a way that encourages them to fork. Hence in a no dig plot, all soil can be fed, and roots are still good to grow. It is not the compost which makes roots fork, as you so often hear, but the fact that it is usually turned into the soil, creating pockets of uneven fertility.
Broad beans and peas are two top vegetables to sow now. I find that beans do well from direct sowing, and peas grow more reliably from sowing in modules or pots, with a mousetrap nearby. Rodents are harder to manage in the open soil, and if you suspect mice or rats it is worth sowing your broad beans undercover in pots, then plant them when just two inches high, before the roots are too restricted. Peas root less vigorously and transplant more easily than broad beans, usually after about three weeks in the greenhouse.
If you did not save pea seed last year (really worthwhile!), be sure to buy a variety which suits your needs, in terms of how high it will grow, which can be anything from two to seven feet. Tall peas need more room laterally and crop a little later, with higher yields. Be wary of yellow and purple peas, however pretty they are, unless you want more beauty than food. Hurst Greenshaft is three feet high and Alderman grows to six feet, both are excellent flavour. Tall Sugar Snap is even higher and you can eat the pods too. Tall varieties are best for pea shoots and the close spacing above (9-12in) is for growing pea shoots.
March is top month for sowing spring salads, but what are spring salads? Apart from taste preferences, there is a seasonal aspect if you want longer-lived salad plants, because all brassica salads such as mustards, rocket, pak choi and mizuna will flower in May, whether they were sown last autumn or are sown now. So a spring sowing gives a short period of picking, as well as leaves with more holes from flea beetles. The picture on right below is of mustards and mizunas that were sown last September, still giving leaves now but they will indeed flower by late April.
If you want longer lived plants to sow now, lettuce is the number one, with potential for healthy, weekly harvests off the same plant for twelve weeks in fertile soil. Sow now, space plants at nine inches (22cm) and start picking outer leaves by about early May, then every five to seven days until July. Sow once more (just once!) in early to mid June for harvests through late summer and until early October. This works best in damp soil enriched with sufficient organic matter, whereas on lighter, thinner soils your plants may crop for only six to eight weeks, necessitating an extra sowing or two: have a go and see.
Of leaf varieties, my favourites are Chartwell (green cos), Rosemoor and Nymans (red cos), Freckles (speckled cos), Rouge Grenobloise and Maravilla di Verano (bronze batavians), Bergamo (pale, bright lollo) and even Little Gem for smaller leaves. Varieties described as “hearting” can be picked of their outer leaves, and the only ones I don’t grow are butterheads, whose leaves are rather flimsy, and soft and difficult to pick as they lie on the soil.
Also good to sow now are early cabbages, cauliflower and calabrese, always checking the varietal description to make sure it is for early sowing. For example there are varieties of cabbage for winter cropping, best sown in May or early june, and of cauliflower for spring cropping next year, best sown in early June, when it also works well to sow kale and purple sprouting broccoli. So be selective in your sowings, sow what is in season and enjoy better results.
Finally, you can be sowing salad onions, beetroot indoors preferably (better in April if outdoors), outdoor carrots at month’s end, and herbs such as dill, parsley, summer savory and thyme. Onion sets and shallots can go in, also first early potatoes. The forum has many questions and answers for no dig potatoes, the one vegetable which needs a slightly different approach.
Weeding is going to happen soon, or NOW if you have a residue from last autumn or winter. Remove those as soon as you can, before they seed, and to reduce habitat for slugs. Then watch for the first germinations of tiny annual weed seedlings which can immediately and most easily be removed by a gentle swish through the surface with a rake or hoe. Simply moving them sideways, preferably on a dry day, is enough to dislodge the roots of little seedlings and prevent them growing, and is so much quicker than dealing with larger weeds.