A seed tray that comes up thick with seedlings is a hopeful sight, but left crowded they grow weak and spindly. Moving them on into their own space, called pricking out, is a gentle, fiddly job that turns a green fuzz into proper plants.
The right moment
Wait until each seedling has its first pair of true leaves, the ones that appear after the rounded seed leaves and actually look like the plant. Any earlier and they are too fragile to handle; much later and the roots tangle together.
Handle them by the leaf
This is the golden rule that saves seedlings. The stem is the part that cannot recover if it is crushed.
- Hold a seedling only by a seed leaf, never the stem.
- Loosen the roots from below with a dibber or pencil.
- Lower it into a hole in its new pot and firm gently.
Settling them in
Set each seedling a touch deeper than it grew before, water it in with a fine rose to settle the compost around the roots, and keep the new pots out of harsh direct sun for a day or two while they recover from the move.
Potting on later
As the young plants fill their pots, move them up a size again before the roots circle and choke. Each step gives fresh compost and room to grow, and by planting-out time you have strong, well-rooted plants instead of starved, leggy ones.