By Sarah Buchanan. First published by Rattan Direct on 8 June 2016.
Follow our tips for planting out seedlings of green leafy veg and leeks
When seedlings are at least 10cm tall:
- Water them well the day before you plan to move them
- Dig over and clear any weeds from the place you want to plant them
- It’s best to move the seedlings in the evening, when it’s cooler
- Use a trowel to make a small hole in the soil, about 10cm deep and as far apart as the seed packet suggests: cabbages and greens are usually around 30cm (about a 12″ ruler). Planting out doesn’t have to be in rows but it can be easier to care for and harvest plants if you do that. The space between rows should follow the seed packet advice; for green veg it is usually about 30cm apart
- Fill each hole with water and let the water drain away
- Next, separate the seedlings. Seedlings in pots need to be tipped out gently (sideways, not head first!) onto a spare seed tray or plastic sack, and seedlings in the ground need to be eased up and out with a small hand fork
- Drop a seedling into each hole, firm the soil around them with your hands and water them well.
Some green veg plants, such as cabbage, are prone to cabbage root fly. You can head these critters off in one of four ways.
Option 1
Fit a ‘brassica or cabbage collar’ around the base of the seedling’s stem to stop the female fly laying eggs on the soil close to the plant. Ready-made collars can be bought from garden centres.
Option 2
DIY with circles or squares, about 8-15cm across, cut from carpet underlay, roofing felt, cardboard or something similar.

Option 3
Protect the seedlings or plants by growing them under a loose tunnel or the cover of horticultural fleece or insect-proof mesh.
Option 4
Use ‘Nemasys Grow Your Own’. This mixture of pathogenic nematodes is sold as a biological pest control and used against cabbage root fly larvae and other pests (including carrot fly, onion fly, leatherjackets, chafer grubs, sciarid flies, caterpillars, gooseberry sawfly, thrips and codling moth).
Longer term, reduce the risk of cabbage root fly by ensuring you don’t grow the same plants in the same place every year (crop rotation).
Special treatment for leeks
Leeks – the must have veg in so many recipes – need some special treatment. We want to eat long straight stems, so planting out starts them off in deeper holes with clear edges (so they look like a tube).
- Ideally use a ‘dibber’ to make holes 15cm deep, 15-20 cm apart and in rows about 30cm apart
- Fill each hole with water, pop the seedling in and re-fill the hole with water again – no need to firm the soil around the seedling
- No dibber? Use a trowel but make the hole as much like a tube as you can. Or shape an old tool handle to create a point.

Care and protection
Seedlings grown indoors or under shelter are likely to need some protection from winds or a day of too-hot sun. Put a loose layer of horticultural fleece over them, or over a ready-made or make-shift tunnel, for a week or so until they look settled.

Seedlings of tender plants – such as courgettes, pumpkins or beans – are best moved into a larger pot until they are small plants, then follow our tips for planting out.
Keep an eye on your vegetable youngsters
Water seedlings and plants, using a spray or rose on your watering can or hose, each evening for at least a week or so after planting out. Watch out for damage by slugs, snails or other pests, and take action to keep your veg for your table. Some seedlings or plants may fail – fill the gap with any spare seedlings of the same type. If there are lots of gaps it may be worth using the space for another plant – sow carrots, lettuce or another quick crop.
And if you didn’t sow seeds – buy ‘strips’ of seedlings or small plants, and follow the tips above to plant them out.