Spring on a British vegetable plot doesn't arrive on one tidy date. One week the ground is cold and sticky; the next, the weeds have doubled and the first aphids have found the purple sprouting broccoli. Working to the season rather than the calendar is the sensible approach, but a month-by-month plan still earns its keep. Here is what to sow, feed, weed and watch from March to May.
March: Wake the Beds Up
Soil first, seed second
Before you sow anything, walk the plot and test the ground. If the soil forms a sticky ball that holds water, wait. Digging wet clay does lasting harm — you compact it into something closer to brick. Cover the beds you plan to sow first with black polythene or a cloche for a fortnight. That warms the top few centimetres and dries it enough to rake into a decent tilth. Spread a couple of centimetres of well-rotted compost on beds that had none in autumn, and fork it into the surface layer without turning the soil over.
What to sow in March
- Broad beans — direct where they are to crop, or started in modules if your soil is heavy
- Onion sets and shallots, pushed in so the tips barely show
- Early peas under cloches, or in lengths of guttering indoors
- Hardy salad leaves: land cress, winter purslane, a first cut of lettuce under cover
- Radish and spinach in short rows, sown little and often
- Parsnips — but only once the soil has lost its chill, as the seed sulks in a cold bed
- Tomatoes, peppers, aubergines and brassicas in modules under cover
Potatoes chitting on a windowsill can go in from late March in milder areas, a fortnight or so later in the north. First earlies first, maincrops after.
Weed and watch
Hoe on a dry, breezy morning and the weeds shrivel where they fall. Leave it until the afternoon and you are simply spreading them. Bittercress, chickweed and groundsel set seed fast, so catch them before the flowers open. While you are out there, check the soft new growth of anything overwintered — aphids gather quietly on the undersides of leaves long before you notice curling tips.
April: The Busiest Few Weeks
Sowing and planting out
By April the soil is workable and everything seems possible. Sow beetroot, carrots, chard, lettuce, spring onions, turnips and mangetout in short rows rather than one long one, so you can cover them easily if the forecast turns. Plant out hardened brassicas, leeks and module-raised onions. Sow sweetcorn, courgettes, squash and pumpkins indoors towards the end of the month — they germinate quickly and resent being held in a pot too long.
Thin carrots and parsnips in the evening, when the scent of bruised foliage is less likely to draw carrot fly. Water the row afterwards to settle the soil around the seedlings you keep.
Harden off properly
Give plants a week to ten days of adjustment: days outside in a sheltered spot, nights back under cover, slightly less water than they were used to. Tender plants pushed straight from a warm windowsill into an April bed rarely forgive you.
May: Protect What You Have Grown
Frost is still a real risk across most of the country until late May, and in northern areas into early June. Keep fleece and cloches within reach, and resist planting out tomatoes, runner beans, French beans and sweetcorn until the nights have settled. A doubled layer of fleece will pull a tender crop through a light frost; a cloche or cold frame does more.
- Earth up potatoes as the shoots break through, leaving just the tips showing
- Pinch out the growing tips of broad beans once the first pods set, which discourages blackfly
- Pinch out tomato sideshoots weekly and tie stems to their supports
- Net brassicas with fine mesh before the butterflies arrive
Water in the morning where you can. Evening watering leaves foliage damp overnight, which suits slugs and mildews far better than it suits your plants.
Feeding: Little and Often Beats One Big Dose
Spring feeding starts with the soil, not the bottle. If you dug in compost or well-rotted manure over winter, most crops need very little extra. A general-purpose organic fertiliser raked into the surface a week or two before sowing covers hungry crops such as brassicas and potatoes. After that, feed the plants that are actually growing: a diluted seaweed feed every fortnight for leafy salads and kale, and a tomato feed once the first flowers set on fruiting crops.
Go steady with nitrogen. Too much produces soft, sappy growth that aphids adore and that ripens poorly — you get enormous leaves and very little to eat. Never spread fresh manure around growing plants; it can burn roots and carries weed seeds.
Weekly Pest and Disease Checks
Ten minutes with a mug of tea is worth more than any spray. Run through the same short list each week:
- Turn leaves over and look for aphids, whitefly and clusters of eggs.
- Check brassicas for caterpillar damage — small holes and dark droppings mean something is at work.
- Look for silver slug trails and nibbled seedlings at dusk; beer traps, night patrols or a biological control used at the right soil temperature all help.
- Watch for carrot fly, which flies low, so a barrier of fleece or a mixed row with onions and leeks reduces the damage.
- Inspect potato foliage during warm, humid spells for the dark patches that signal blight, and remove affected leaves promptly.
- Check the base of stems for rot, and clear yellowing leaves rather than leaving them on the ground.
Keep a Note, Then Adjust
Write down what you sowed and when, roughly when it germinated, and which beds did best. Two lines a week is plenty. Your soil, your slope and your shelter all differ slightly from any general guide, and a spring's worth of notes will tell you more than the calendar ever will. Treat the checklist above as a starting point — ignore it wherever your plot knows better.
Photo: stevepb / Pixabay
