Advice
Transplanting vegetables
Some vegetables - including leeks and brassicas - are best started into growth in a seedbed or nursery and then transplanted to their final growing position.
When transplanting vegetables aim to minimise the damage to the roots and slowing of growth that the shock that transplanting can cause. Slowed growth delays maturity and reduces final yield. In extreme cases the check to growth of transplanting can lead to bolting or premature seedhead formation instead of the expected roots, hearts and curds.
Before digging transplants from a seedbed, called bare-root transplants, water them and the soil well about a day before lifting to ensure the plants are full of water (turgid). Leeks should be no more than pencil thickness and cabbage family or brassica crops should have five to seven true leaves. If plants have been raised under cloches or in a cold frame increase ventilation for two weeks before planting out. Keep plants in a shaded place in a bucket of water if not planting out immediately.
Plant brassicas by making a hole with a trowel, big enough to hold the transplant's roots. Place the transplant in this up to the depth of the true leaves, and fill the hole with water several times, then firm the soil around the plant. Transplants are sufficiently firmed in if the leaf tears when you try to pull one out of the ground.
Plant leeks by drawing a groove or drill in the soil with a hoe and make planting holes with a trowel or dibber. Place one leek in each hole and water in carefully. This will cause some soil to accumulate around the roots. Dipping the leeks' roots in a bucket of water before planting will make the roots dangle, easing the job of getting them into the planting hole.
Although shortening of roots or trimming foliage is sometimes recommended to make the plants easier to handle or in a misguided attempt to reduce stress on the plants, in fact this reduces the plants capacity to recover. Avoid trimming as far as possible. Shading is also detrimental and should only be necessary in the hottest weather. Watering and the application of high phosphorus liquid fertilisers, on the other hand, will aid establishment.
Pot- or cell tray-grown transplants are easily planted as long as they and the transplanting site are watered thoroughly the day before planting. Take out a hole big enough to accommodate the rootball. Plant firmly, aiming to plant no deeper than the transplant was in the original container.