With Charles Dowding
There are simple ways to achieve this, says Charles
What a difference it makes when your harvests are early, especially in spring when fresh vegetables are scarce. Even at this late stage, there are simple methods for achieving this, in particular to do with sowing undercover, and covering new plantings and sowings with fleece.
Soil treatment is important and a no dig approach helps, because the capillary link to soil warmth in Earth’s deeper layers remains intact. Studies by the Scottish Fruitgrowers’ Research Association in the 1940s showed 1.5C higher soil temperatures in no dig soil, on frosty nights.
This was highlighted by F.C. King, head gardener at Levens Hall, Cumbria, in his 1951 book The Weed Problem. In a similar vein he noticed earlier blossom every year on a plum tree whose soil was undisturbed, compared to a neighbouring tree of the same variety whose soil was dug every winter.
Soil preparation for early cropping
In the damp British climate, a mulch of well decomposed compost is better than any unrotted mulches, and not only because of reducing slug habitat. Compost (which includes old animal manure) is dark and warms nicely in any sunshine, when spread on the surface and not incorporated. It looks like a black blanket over the soil, even like dark soil, causing a few visitors to Homeacres to ask why I do not mulch!
When spreading compost in spring as opposed to autumn, it’s important to break any larger lumps while loading the wheelbarrow. Old animal manures often have lumps of less decomposed material, straw still yellow even, and put these on one side to decompose further. On your beds, have no pieces larger than a golf ball, to make sowing and planting easier.
If your soil has couch grass, creeping buttercup etc in any quantity, early cropping is more difficult and I suggest using such areas for later plantings, after mulching with polythene. When weeds are thick and persistent, grow crops such as courgettes and potatoes which you can plant through holes in the polythene.
Weed strikes now for annual weeds
The aim is a 100% clean surface when sowing and planting, yet most compost contains plenty of weed seeds. It works best to eliminate them before sowing and planting, to save time later. Any day now, and as soon as you see a faint shimmer of tiny green weed shoots, run a hoe shallowly and horizontally, through the compost to disturb the germinating seedlings.
Another option is to pass a rake across the top, lightly and in a sideways, sweeping motion through the compost mulch. As well as killing weed seedlings, this gives you a finer tilth on top.
Early weeds include fathen, chickweed, bittercress, groundsel, shepherds purse and annual meadow grasses. Hoe or rake them before you see the first true leaves. Grasses are an exception because of their tenacious roots, which may not die after
hoeing unless it’s very dry. If the grass is more than tiny, you need to hand weed before their roots become tenacious.
Meanwhile, sow undercover
While ground is coming ready and you are reducing weed numbers, sow many vegetables undercover, at appropriate times. In late March and early April there is still just time to sow onions, celeriac, tomatoes, lettuce, early brassicas and beetroot. By mid April it’s good to sow leeks, chard, courgettes, squash, basil and sweetcorn.
First sowings outside
Spring has wild fluctuations of temperature and sometimes you need to wait for frosts to clear, as in March 2013 when I sowed nothing outside until the first outdoor sowings that year on April 6. Use a fleece cover over early sowings, directly on the ground to trap warmth in the soil, whenever the sun appears.
Late March to early April is best time for outdoor sowings of spinach, lettuce, peas, onions, spring onions, early brassicas and turnips, radish, coriander, dill and parsley. Sow first early potatoes in late March, then second earlies in mid April. There is no rush to get potatoes in the ground, unless you are fortunate to suffer no frosts in May. Fleece is worthwhile if late frost happens in your area.
Planting outside and fleecing over
You can save time by taking plants straight from the propagating area, without hardening off, to plant into surface-composted soil, even in cold, windy weather. After planting and sowing, simply lay the fleece on top of plants.
A fleece cover over the top helps plants adjust to their new environment, by protecting them from cold wind, at the same time as allowing air to ventilate, and most rain to pass through. Any spells of sunshine are quickly converted to warmth and held close to plants, when fleece is sitting right on top of their germinating seeds or seedling leaves.
Laying fleece at ground level saves time and materials - no hoops, and all you need is stones, sand bags or stakes along the sides. It’s quick to roll or lift off these weights to pull back the cover, temporarily, for any weeding needed.
More about fleece
Buy 25 or 30gsm and then the covers should be reusable, many times. For weather protection, it’s no problem if there are a few small holes. Fleece of 2m width is good for vegetable beds of most dimensions, and its light enough that leaves are happy to push it up as they grow. It’s pleasing when you see covers rising like bubbles over your plantings.
There is no advantage to laying a fleece cover before sowing and planting, as the soil’s warmth retention is so temporary. I had this comment from a teacher, on my website forum: “I did an experiment with some children with clear plastic, black plastic and with cardboard, and we found no notable difference compared to uncovered ground, just 1C.”
Removing fleece covers
This depends more on weather than on plant size. In 2016 and 2017 we took covers off in the first week of May, after most frosts and cold winds had finished. In other years it has been sooner, and in cold areas it may be later, also depending on which vegetable is growing.
For courgettes and sweetcorn, I plant mid May and keep fleece over for just one or two weeks, unless it’s unusually warm and they don’t need it. For beds of mixed spring vegetables, I remove fleece early May once plants are growing strongly, often with some spinach and lettuce leaves ready to harvest.
Joyful first harvests (they always taste special) come every week through spring. Bring them forward with picking methods such as regular removal of lettuces’ outer leaves, pinching off pea shoots and thinning carrots and beetroot.
I am usually picking hearts of Greyhound cabbage by late May, from sowings on Valentines Day. Then beetroot Boltardy by early June, calabrese and early potatoes soon after, all to look forward to. MORE: www.charlesdowding.co.uk
After removing fleece covers in early May, vegetables are growing strongly
Charles making lines to plant lettuce in the dark compost
Fleece rolled back to pull weeds in the spinach bed