Once your seedlings have got to about half an inch (1.5 – 2 cm) it is time to move them.
This short video shows you how to ‘pot on’ your seedlings to give them more space.
It’s quick and easy but you have to be delicate!
- Wait until the secondary leaves appear, these are your plants first true leaves and will show signs of the leaf form expected in the mature plant. The seedlings should also be about half an inch (1.5 – 2 cm) in height or – slightly more depending on the plant type and variety – as this will make them easier to handle plus if replanting too early the seedlings will be weak and could easily get damaged.
- Before handling your seedlings you must first prepare something for them to be transplanted into. Use seed trays as your young plants will grow quite happily this way, there is no advantage whatsoever to using cells or small plant pots.
- Fill each of your seed trays or other containers almost to the rim with reasonable quality multi-purpose or seed and cutting (or seed and sowing) compost, firm your compost down lightly and then water it thoroughly. Water before replanting the young plants or seedlings as this causes less disturbance to the plant itself. Once replanted you will still need to water your plants otherwise they will never grow. Allow your excess water to drain out before planting anything into the tray, pot, or cell so be sure to make certain that whatever container you are replanting your plants into has a hole or holes in the bottom to allow this excess water to drain away freely.
- Next use a process known as ‘pricking out’, this is the act of removing your seedlings from their initial seed tray and replanting into some other container without causing them any damage .
To do this the compost in which your seedlings have germinated and began to grow in needs to be moist so water it if required as hard dry compost will make the pricking out process more difficult and is more likely to damage your young seedlings.
- A special tool known as a ‘dibber’ can be used if you wish, this is effectively no more than a thin tapered stick to prise out your seedlings and make a transplanting hole, and is usually made of wood or plastic. The end of a pencil works just as well and is cheaper.
- Make a small but deep hole in the surface of the compost you are going to transplant your seedlings into using your dibber or pencil point. Then insert your dibber or pencil point into the compost alongside the seedling you would like to replant and carefully lift the plant along with the roots using the tool. Make sure that some compost is still attached to the roots of the seedling and then with your other hand hold the seedling by the leaves and carefully lift whilst prising out the roots with the tool.
- Always handle your seedlings or young plants by the leaves and not the stem. This is to minimise the damage to your young plant as handling it by the stem can cause it to be crushed or snapped and of course will render the plant useless, so if this happens it is best to discard it and try again; whereas damage to the leaves will have no detrimental effect on the plant itself and it will continue to grow as it should.
- Immediately transfer your young plant to the compost with the hole in you made earlier and carefully tease the roots using your dibber or pencil point into the hole, try to use your dibber or pencil point rather than your fingers to minimise damage to the roots. Once done lightly firm the surrounding compost around your young plant to close the roots in, remembering to leave the bulk of the stem and leaves above the surface of the compost. Discard any seedlings that appear weak, flimsy or small because the chances are they will not grow properly anyway; there’s no room to go soft over the runt of the litter here, if it’s weak, feeble or too small get rid of it.
- Space your replanted young plants about 2 inch (5 cm) apart in their trays or use one plant per cell or pot. As a guide a half-sized seed tray will hold 12 young plants (4 long x 3 wide).
- With really small seedlings like lobelia, it is much more practical to prick out 2 to 4 seedlings together.
- Return your pricked out plants to the greenhouse, cold frame or windowsill and allow them to grow on. Water as and when necessary, the compost should always be moist but never soaked. No glass or other cover is required at this stage so put it away for next season.
In a few weeks your young plants will have grown enough to ‘harden off’.