Plant Propagation: Pricking out Seedlings

If you are new to raising plants from seed, here are a few tips on pricking out seedlings!

When do you know that your seedlings are ready to prick?

If you look at your seedlings, you will see the very first leaves to appear look different to the leaves that follow. The first leaves are called the seed leaves and are usually quite simple. The ones that follow - called the true leaves -  look more like miniature leaves of the mature plant.

A good rule of thumb is to wait to prick out seedlings until the true leaves appear. At that stage, the roots will just be starting to branch. If you wait until the seedlings are much bigger, they will suffer more from transplant shock as the roots will be more damaged than when they are smaller, and will tangle more with their neighbours!

The Process

Okay, here we go! You will need some potting mix, containers to hold your seedlings until they are big enough to plant out, and a dibber/dibble which can be as simple as a pencil or ice cream stick to lift seedlings/make holes etc.

Fill your punnets/pots with potting mix, and water them so they are nice and damp. Ensure the seedlings you are about to prick  have been watered as well, but are not sodden. Doing this 2-3 hours prior to pricking is ideal.

Use your dibber to make holes for the seedlings in the centre of each pot/cell.

Tip: If you form a cone-shaped hole, the roots of the seedling will go in more easily without getting caught on the sides.

Make sure that the holes are deep enough for the roots- avoid jamming the roots in shallow hole.

Remove a small clump of seedlings at a time,  making sure to lift them out from the bottom of their tray, so that the roots are damaged as little as possible. Hold the seedlings by the true leaves and gently tease them apart. 

Lift a seedling, holding by its true leaf, lower roots into the hole until the soil is just below the seed leaves and firm in gently.

Make sure that the roots go down and don’t get caught up. If the roots are very long, you can pinch them back a little.

Note:  avoid burying the bases of the leaves where they are attached to the stem as this could cause rotting. (Brassicas and tomatoes don't mind). 

Note: discard any seedlings that look unhappy, or have very little roots – they will struggle and often end up as sick plants.

After filling all the cells,  tap the punnet firmly on the table to settle the soil around the roots.

Water seedlings soon after pricking (or stand them in a shallow dish of water).

Keep out of sun for the day, to allow the plants to recover. I like pricking in the afternoon as it gives the seedlings the night to settle in.