Plants and Gardening

What to Plant This Month UK

What to Plant This Month (UK)

Welcome to our UK monthly planting calendar — your year-round guide to what seeds to sow, plants to transplant, and crops to harvest each month. British weather keeps us on our toes, but this calendar helps you stay one step ahead. Whether you have a sprawling vegetable patch or a modest patio container garden, follow these monthly prompts to keep your garden productive through every season. Timing varies slightly by region: gardeners in Cornwall and the south-west can start two to three weeks earlier than those in northern Scotland or exposed northern gardens. Adjust these dates to your local microclimate and always check soil conditions before sowing.

What to Plant in March

March marks the true start of the gardening year. Daylight stretches past twelve hours, soil begins warming, and the first direct outdoor sowings become possible. This is your busiest sowing month — get it right and you will harvest well into autumn.

Seeds to Sow Indoors (Heated propagator or warm windowsill)

  • Tomatoes: Sow now for greenhouse crops. Use seed compost, keep at 18–21°C. Transplant to individual pots when two true leaves appear.
  • Peppers and Chillies: These need a long growing season. Start early in heated propagators; they germinate slowly in cool conditions.
  • Aubergines: Similar to peppers — warmth is essential for germination. Sow one seed per small pot.
  • Celery and Celeriac: Slow germinators requiring consistent warmth. Prick out carefully as seedlings are delicate.
  • Onions from seed: Sow in modules for transplanting later. Produces larger bulbs than sets in favourable conditions.
  • Leeks: Start now for autumn and winter harvesting. Easy to germinate; transplant in June.
  • Lettuce and Salad Leaves: Succession sow every two weeks for continuous harvests. Start early varieties indoors.
  • Brussels Sprouts: For Christmas harvests, sow now. They need a long growing season and firm planting later.
  • Early Cabbage and Calabrese: Sow for summer harvests. Transplant when 10–15cm tall.
  • Sweet Peas: Sow in deep pots or root trainers for strong root systems. Pinch out tips when four pairs of leaves form.

Seeds to Sow Outdoors (Direct into prepared soil)

Only sow when soil is workable and no longer waterlogged. Cover with fleece if cold nights threaten.

  • Broad Beans: Sow direct in mild areas or start in pots for transplanting. Hardy and reliable for early harvests.
  • Peas: Sow in trenches or use guttering for easy transplanting. Protect from mice and pigeons.
  • Parsnips: Wait until soil has warmed slightly. Parsnip seed is notoriously variable — sow thickly and thin later.
  • Early Carrots: Choose fast-maturing varieties. Sow in drills and cover with fleece to prevent carrot fly.
  • Beetroot: Soak seeds overnight, sow in drills. Each ‘seed’ is actually a cluster — thin to one seedling per station.
  • Radish: Fast germination — harvest in four to six weeks. Sow little and often.
  • Spinach and Perpetual Spinach: Hardy and productive. Sow in short rows for manageable harvests.Swiss Chard: Beautiful and productive. Tolerates light frosts once established.
  • Spring Onions: Quick and easy. Sow every three weeks for continuous supply.
  • Land Cress and Mizuna: Hardy salad leaves for cut-and-come-again harvests.
  • Parsley: Slow to germinate — soak seeds first. Patient gardeners are rewarded with year-round supply.

Plants to Transplant Outside

Harden off all indoor-raised plants for a week before planting out. Wait until risk of hard frost has passed in your area.

  • Onion Sets: Plant in well-prepared soil, tips just showing. Birds love pulling these out — cover with fleece or netting.
  • Shallots: Plant individual bulbs 15cm apart. Each bulb splits into a cluster for summer harvest.
  • Early Potatoes: Plant second early varieties in early March in mild areas, late March further north. Earth up as shoots emerge.
  • Asparagus Crowns: Plant dormant crowns in prepared trenches. Do not harvest first year — let plants establish.
  • Artichoke Offsets: Divide and replant established clumps. Space generously — these are architectural plants.
  • Rhubarb: Divide and replant crowns while dormant. Do not harvest first year after division.
  • Strawberry Runners: Pot up or transplant to prepared beds. Remove flowers in first year for stronger plants.
  • Autumn-sown Broad Beans: If you sowed in November, plants should be established — support with canes if tall.

Crops to Harvest in March

Winter stores run low but fresh harvests begin appearing.

  • Brussels Sprouts: Final sprouts from autumn planting. Remove yellowing leaves to keep plants healthy.
  • Sprouting Broccoli: Purple and white sprouting varieties peak in March. Cut central spear first; side shoots follow.
  • Kale: Hungry Gap varieties provide fresh greens when little else is available.
  • Leeks: Finish lifting winter leeks before they bolt. Heel in any surplus for later use.
  • Parsnips: Last chance to lift stored roots. Flavour improves after frost exposure.
  • Jerusalem Artichokes: Dig as needed. Leave some in ground — they regrow reliably.
  • Winter Salad: Corn salad (lambs lettuce), land cress, and claytonia provide fresh leaves.
  • Early Forced Rhubarb: Forced stems from covered crowns are tender and sweet. Stop forcing by late March to let plants recover.
  • Spring Cabbage: Start cutting pointed varieties. Use promptly for best flavour.
  • Swiss Chard: Overwintered plants produce fresh growth as days lengthen.

Coming Soon: Monthly Guides for the Full Year

New monthly planting guides are added throughout the year. Check back as the seasons progress for detailed advice on:

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