When seedlings become large enough to handle, they should be transferred (transplanted)Transplant to other containers to give them more space to grow. This is known as ‘pricking out’. The seedlings are usually large enough when they have developed their first set of true leaves though some, which may have quite small seedlings, may need to develop more than one set before they are ready.

If you leave seedlings too long before transferring them, their rapidly developing roots can become difficult to untangle and relocation can easily damage the young plants.

Always treat the seedlings with great care and use an implement such as an old kitchen fork to lift them. If they are too crowded to lift individually, lift them in clumps and then gently tease them apart causing as little damage to the roots as possible. Hold the young seedlings by their leaves and never by their stems – it is easy to crush these delicate plants and if that happens to the stem, the plants will die.

Drop the roots of each seedling into a hole in the fresh compost then gently firm it down. If planting in trays, the holes should be about 3cm apart. By planting the seedling slightly deeper than it was before, the tender stem will be well supported and shouldn’t fall over – this is particularly important for seedlings such as tomatoes which tend to have long stems below the first leaves (the seed leaves or ‘cotyledons’) but you must ensure that the lowest leaves are above the surface of the compost.

When you have completed the tranferring of your young seedlings, the trays or pots should be watered from below or, if this is not possible, gently from above with a fine rose.

Never use very cold water on seedlings.

Return the seedlings to a position where the temperature and light are similar to their previous location. Keep them moist but there should still be no requirement for feeding. Once they are well established, they will need regular feeding with a good, balanced liquid fertiliser at the manufacturer’s recommended rates. If they become overly large or crowded before conditions are right for planting out, don’t be afraid to pot them on again into larger cells or pots.

Before they can be planted outside, your seedlings will need to get used to the conditions in your garden. Plants in the protective environment of a windowsill or greenhouse tend to be rather soft and may suffer if placed directly outside. To acclimatise them to life in the open air, put your seedlings outside in a warm and sheltered spot during the day and bring them in at night for a period of about two weeks. This is known as ‘hardening off’.

See Also:

Planting Out