Transplanting vs Direct Sowing
Some vegetables are easiest and most reliable when started in pots or module trays, while others prefer seed sown where they will grow. Choosing the right method saves space, reduces losses and helps match crops to British weather. Use both approaches to create a flexible planting routine through the season.
Decide first whether a crop dislikes root disturbance or benefits from an early start. Direct sowing means placing seed straight into its final bed. It suits carrots, parsnips, peas, broad beans, radish, beetroot, turnips and many salad leaves. Transplanting means raising seedlings in module trays or pots before planting them out. It is especially useful for brassicas, leeks, lettuce, tomatoes, courgettes, cucumbers, sweetcorn and many herbs. Read the packet before choosing, as varieties vary. Direct sowing is inexpensive and quick, but young plants face weather, birds and slugs immediately. Transplants take more attention under cover, yet give you sturdy plants and a clearer view of gaps before they reach the garden.
Prepare a direct-sowing bed carefully because seedlings will have no recovery period after moving. Remove weeds and stones, add garden compost if needed, then rake the upper surface fine and level. Make shallow drills with a cane, following packet guidance for depth and spacing. Water the drill base first when conditions are dry, sow thinly and cover with soil. Firm gently, label the row and keep the surface evenly moist until seedlings emerge. Do not sow into cold, saturated ground simply because the calendar says spring. A short delay often gives faster, more even germination. Protect seedlings with fleece or a cloche if cold winds, birds or persistent rain are likely.
Use module trays for crops that transplant readily, filling each cell with moist peat-free multipurpose compost. Sow one or two seeds per cell, covering them to the required depth, then place trays in bright conditions. Thin to the strongest seedling if both germinate, using small scissors rather than pulling roots. Water from below or around the modules so seedlings remain upright and disease risk is reduced. Once roots hold the compost together and the plant has several true leaves, it is usually ready for gradual hardening off. Do not leave seedlings cramped for too long. Rootbound plants can stall after planting and are harder to establish than smaller, well-timed transplants.
Harden off indoor-raised plants for seven to ten days before planting outdoors. Put them outside in a sheltered, lightly shaded place for a few hours initially, then increase exposure daily. Bring tender plants back under cover if frost or harsh winds are forecast. Plant on a calm, cloudy day if possible. Water modules before lifting them, make holes large enough for the root ball, set each plant at its previous depth and firm soil around it. Water thoroughly after planting. Brassicas benefit from firm planting because they need stable roots; tomatoes can be planted slightly deeper if their stems are long. Keep newly transplanted crops shaded briefly if strong sun follows immediately.
Match the method to timing and available space. Direct-sow radishes, rocket and salad leaves in short rows every two or three weeks for continuous picking. Start cabbage, kale and lettuce in modules, so beds are not occupied while an earlier crop finishes. Raise tender tomatoes and courgettes under cover from April, then plant after frost risk has passed. Use biodegradable pots cautiously: if the rim remains above soil it can draw moisture away, so ensure it is fully buried. For peas and beans, direct sowing is simple, but module-grown plants can be useful where mice, pigeons or slugs repeatedly destroy emerging shoots. Trial both methods in small batches and compare results.
Care after sowing or planting determines whether either method succeeds. Check direct-sown rows frequently, thinning seedlings before they compete and weeding while weeds are tiny. Replace failed transplants promptly with spare modules if you have them. Water at the base, especially during the first two weeks, but avoid making soil constantly saturated. Use netting where pigeons target brassicas and peas, and inspect beneath cloches or fleece for slugs. Record sowing dates, germination and planting dates in a notebook. Over time, you may find that a windy allotment favours module-raised brassicas, while a sheltered garden gives excellent direct-sown salads. Let those observations shape next season's plan.
Frequently asked questions
Which vegetables should never be transplanted?
Carrots and parsnips are best direct-sown because disturbed roots can fork or become misshapen. Radishes and many root crops also perform most simply when sown in place. Peas and beans can be transplanted carefully, but they usually establish well from direct sowing unless pests or poor weather make early protection necessary.
How big should seedlings be before planting out?
Plant when each seedling has several true leaves, a root ball that holds together and is not tightly coiled, and a sturdy stem. The exact size varies by crop. Do not wait for oversized plants. A young, hardened-off seedling usually settles faster than one that has become crowded in its module.
Why are my direct-sown seedlings disappearing?
Slugs, birds, mice, cold weather and drying soil are common causes. Check the bed at dawn or after rain for slug damage, use fleece or netting where appropriate, and keep the seed zone evenly moist. Sowing a few spare seeds in modules provides replacements without delaying the whole crop.
General guidance for UK home gardens and allotments. Conditions vary by region, soil and season; the RHS or a local garden centre can give site-specific advice. Page updated 19 Sep 2026.