Transplanting Seedlings

If you have started by germinating your seeds indoors, there will come a time when you need to transplant the seedlings – either still in the greenhouse or by planting out into the garden.

Fortunately there are some simple tips for transplanting and pricking out that help you avoid disaster, keeping your seedlings healthy and making sure you don’t lose the entire crop!

When To Transplant Seedlings?

Should you be thinning out the seedlings, instead?

Overcrowded butternut squash seedlings
© Veg Patch Diaries

Firstly, it’s important to check whether the seedlings actually need to be transplanted. Thinning out seedlings might be the better option.

Often, if you have planted, say, two seeds in a pot or tray, using a small pair of scissors to snip off the weaker seedling at the base is the first thing to do.

This might sound unkind, but it might give your stronger seedling a better chance than transplanting it and disturbing its roots at too early a stage.

If you have lots of seedlings in a single tray, you can thin them by watering them well in the morning, to make sure the soil isn’t too firm – or pulling out one seedling could also pull up the rest! Then, a few hours later, gently pull out the weaker seedlings, to leave more space for the stronger ones.

If you planted outisde, the same process applies. Either gently pull out or snip back the weaker seedlings, to achieve the plant spacing suggested by the seed packet.

When to transplant seedlings?

Ideally, you want to transplant your seedlings once they have 4-6 full-sized leaves (we’re not including the two ‘baby’ leaves that first appeared on sprouting). You should pot on when the plant is strong and before it becomes pot bound – i.e. before it has too many roots for the pot.

Preparing seedlings to transplant

Try not to let your seedlings dry out in the few days before planting on, as this would cause them stress and weaken them. You want the soil to be moist, so the roots come out easily, with less damage.

Also, avoid transplanting when it’s very sunny – wait till the seedlings are in the shade – otherwise they might wilt, before their roots have got over the shock of the move and taken up fresh water.

How To Transplant Seedlings / Pricking Out Seedlings

If your seedlings are in single modules or pots, it’s easy. Otherwise you need to be careful to minimise root disturbance, as you get the seedling out.

If your seedlings are in a larger tray together, then you need to ‘prick them out’, in order to pot them on.

I have a very cheap plastic tool for this now, but before I found that, I used to use a teapsoon (very small spoon).

• Prepare the new pots by putting some soil in the bottom, so that the height of the final plant will be what you need, allowing for the soil you’ll be transplanting.
• Gently squeeze the module or pot, to loosen the soil from the edges.
• Use a small trowel or spoon to lift out the plant.
  For larger plants, such as courgettes, you can put your hand over the top of the soil and tip the pot upside down onto your hand, with the stem and leaves going between your fingers.
  If your seedling is being pricked out from a tray, use a teaspoon or pricking out tool to carefully remove the seedling from the tray – being careful not to damage the roots.
• If you need to hold the seedling, do this by using a strong leaf, rather than the delicate stem, which is easily damaged.
• Place the seedling in its new pot immediately and gently firm extra compost / soil around it.
• Water and leave somewhere at the same temperature as before, that isn’t too sunny, until it recovers.

Prepared pot for pricked out seedling © Veg Patch Diaries

Transplanting seedlings - a little early, but they had outgrown their first home! © Veg Patch Diaries

Transplanted squash seedling - with pricking out tool (green) - ready for topping up with compost © Veg Patch Diaries

Do you have any top advice for transplanting or pricking out seedlings?
Please feel free to share your thoughts or questions via the comments box!