Read the season before you reach for the fork

Early spring in the UK is a moving target. A mild week in Cornwall looks nothing like early March in Aberdeenshire, and the calendar alone will mislead you. Soil temperature is the better guide: once the top 10cm sits at around 7°C and climbing, seeds begin to germinate and roots start moving. Push a hand into the border. If the soil clings in cold, claggy clods, give it another fortnight. If it crumbles and smells sweet, you have a green light.

Work with the weather rather than against it. Dry, bright days are for pruning, mulching and sowing. Wet days are for sharpening tools, sorting seed packets and ordering compost. Keep a roll of horticultural fleece to hand — late frosts catch out the optimistic every single year.

Prepare beds and wake up the soil

Everything you sow in the next few weeks will thank you for a well-prepared bed. Start by clearing winter debris: collapsed brassica stalks, soggy leaves, dead annuals and any weeds that have quietly rooted since autumn. Get them out before they set seed.

• Spread a 5cm layer of well-rotted compost or garden compost over empty beds and let the worms pull it down. There is no need to dig it in.
• Cover bare soil with black polythene, cloches or fleece two or three weeks before sowing. This warms the ground and dries the surface, giving you a head start of roughly a fortnight.
• Fork over compacted corners and paths, and work grit or sharp sand into heavy clay to improve drainage.
• Stay off wet beds. Lay a plank to spread your weight if you must cross.
• Top-dress fruit bushes, rhubarb and established perennials with a balanced general fertiliser, then mulch.

Prune shrubs before the sap rises

Late winter and early spring are the last honest window for pruning anything that flowers on new wood. Cut Buddleia davidii back hard to a low framework of buds, and do the same for dogwoods and willows grown for coloured stems — the fresh growth will carry the best winter colour next year. Cotinus, Hydrangea paniculata and bush roses all respond well to a tidy now, cut back to a healthy outward-facing bud.

Finish apples and pears by the end of March, before the buds break, removing crossing and diseased wood to open up the centre. But keep your secateurs away from anything that flowers on last year's growth — forsythia, flowering currant, lilac, weigela, philadelphus and deutzia. Prune those straight after flowering instead, or you will simply cut off this spring's display. Leave evergreens until mid-spring, when the worst of the frost has passed.

Start sowing hardy seeds

Under cover, warmth-loving crops can begin now. Tomatoes, peppers, aubergines and chillies need 18–21°C to germinate, so a heated propagator or a sunny windowsill is essential. Sweet peas are hardier — sow them in deep pots or root trainers and pinch out the growing tips once two pairs of leaves appear.

Outside, direct sowing depends on your soil and your postcode. In most of the south, hardy vegetables can go in from early March; in the north, wait two or three weeks longer or sow under fleece.

• Direct sow: broad beans, parsnips (always fresh seed), early carrots under fleece, radish, spinach, chard, lettuce, spring onions and rocket.
• Sow in modules: brassicas, leeks, beetroot, perpetual spinach and hardy herbs such as parsley and coriander.
• Chit first early potatoes in a cool, light room, then plant out once the risk of hard frost has passed and shoots are short and green.

Water with a fine rose, label everything — you will forget — and thin seedlings ruthlessly once they are large enough to handle.

The cutting patch: sow now for summer vases

If you want flowers for the house, the next few weeks matter more than any other. Hardy annuals sown now build strong root systems and flower earlier and longer than later sowings. Direct-sow calendula, cornflower, nigella, larkspur, scabious, ammi and annual poppies in drills, or raise them in modules for a tidier row. Sow in short successions every three to four weeks to keep the vases full from June onwards.

Tulips in the ground need a feed as their leaves push through, and marking where they sit saves heartbreak later. Cosmos, zinnias and dahlias can wait — they need warmth, and sowing them too early in cold soil only stalls them. Pick a still, dry morning for cutting later in the season, and sear stem ends in hot water for anything milky, such as poppies.

Lawns, pests and late frosts

Give the lawn its first cut on the highest setting, only when the grass is dry and the ground is firm enough not to rut. Sharpen the blade first — a ragged cut invites disease. Repair bare patches with seed or turf while the soil is still moist, and keep off the lawn during frost.

Slugs and snails are at their most destructive now, nibbling new shoots before you even see them. Night patrols with a torch are remarkably effective, as are copper barriers and encouraging frogs and hedgehogs. Aphids will appear on soft new growth; leave them for the blue tits and ladybirds rather than reaching for a spray.

Above all, keep watching the forecast. A clear, still night in April can still drop below freezing, so hold fleece and cloches ready for tender seedlings and newly planted perennials. Check hedges and shrubs for nesting birds before you cut anything. Then enjoy it — this is the most generous season of the gardening year, and everything you do now pays back tenfold by midsummer.