Sometimes my seedlings are getting a little to large for their initial pots but I am not yet ready to plant out into the garden. So I do what is called ‘potting up’ or ‘potting on’. Potting on seedlings is a common practice in gardening. It involves transplanting seedlings into larger containers than they were previously living in. This is done for several reasons:

By potting up seedlings into larger containers, it enables their roots to continue to grow without getting root-bound. When a plant’s roots are being restricted to the point that they start to grow in circles around themselves, they become tangled and “bound up”. This can reduce the roots’ ability to spread out and flourish after they’re planted out in the garden. Plant health is directly tied to root health, so this means the plants are also less likely to flourish.

As their roots grow larger, they drink more water, and thus dry out more quickly. Potting up seedlings provides them with more soil and water, which helps them grow stronger and bigger.

The potting up process feeds the seedlings! When you transplant seedlings into larger containers, you can add fresh soil and nutrients to the mix, which will help the plants grow even more.

Ingredients

• potting mix (see my recipe here)
• seedlings
• Blood and Bone or other fertiliser

Other equipment

• larger punnets or containers for planting in
• water (misting spray preferred)
• plant labels and pen

Method

For ease of reference and to avoid confusion, I am going to refer to the current container that the seedling is in as a ‘punnet’ and the new container as the ‘pot’.

1. Half fill each pot with potting mix and tap on a hard surface to help the soil settle and eliminate any large air pockets. (When your seedling is sitting on this new soil, you want the current level of soil in your seedling’s punnet to approximately reach the same level as the top of the larger pot so adjust accordingly.) If potting mix is a little dry, give a light mist with water. 

2. Water your seedling so the dirt clings better around the roots and it comes out of the pot more easily.

3. Gently squeeze the sides of your punnet to loosen the seedling. Lightly place your fingers over the top of the punnet with space for the seedling between your fingers, and turn upside down. Give a tap on the bottom to loosen and gently shake the seedling (and soil) out. Do not pull on the stem or leaves. You also want to keep as much soil around the roots as possible so they are not exposed to the air.

4. Place the seedling (and soil) on top of the soil in the new pot then fill in the pot with more potting mix. You don’t want to cover the stem above the current level of existing soil as it could lead to stem rot. (The exception to this is tomatoes and potatoes.)

5. Water the soil to help it settle. Top up with more soil if it needs it.

6. Lightly sprinkle some Blood and Bone around the seedling, avoiding the stem. Water in.

7. Label!

8. Keep moist and protect from harsh sun, if necessary.

Banner photograph by Eleonora Sky from Pexels: https://www.pexels.com/photo/baby-plants-growing-on-a-seedling-tray-7392772/