A few weeks after planting your seeds, the seedlings will be ready to transplant into a bigger pot.
When to transplant your seedlings?
You will know it is time when they have produced their first real leaves, these are usually the second leaf that grows. But don’t get too hung up on that, you will also know they are ready when they look too big for the seed trays or small pots you planted the seeds in.
You can see in the tomato seedlings here in the second photo, the plant on the right has the first big leaves, but the second main leaves are coming through the middle.
The plant on the left just has the first leaves so far.
The cosmos seedlings above were planted in a seed tray and lots have sprouted! These have their real leaves growing, they have a different shape to the big outside main ones.
Watch the process here
You can see and listen to the whole process in the video here of me potting on these cosmos.
But if you prefer to read instructions, then see below.
Get your equipment ready
You will need
- A pot – about twice the size of the pot / seed cell you are moving from, or around 3-4 inches (but whatever you have, just not too small as you want the roots to be able to grow
- Compost – Use the best your budget allows, you can use specialist young plant compost or a peat-free multi-purpose compost.
- Optional A dibber & widger, I use these*
Prepare your pot for the seedling
If your compost is very dry and feels more like sand than soil, add some water to it first, you don’t want it soaking wet, but damp so it sticks together a bit.
Fill your pot with compost, leaving 1 cm space at the top, tap the pot to make the compost more firm, and gently push the compost down. Not too much! Then use a dibber, a pencil or your finger to make a hole in the centre of the compost.
How to move your seedlings from their pots safely
I use the widger tool (I fully admit I didn’t know it had a name!), but you can use a spoon /fork / your fingers to really carefully dig up your seedling, just be really gentle, as you don’t want to damage the roots, stalk or leaves.
Hold the seedling by the leaf, not the stem. and you will see the roots on the bottom.
Place the roots into the hole in the compost, carefully pushing the roots into it.
Place the stem into the hole too, you want the seedling to be able to stand up firmly.
Press the soil in to fill the hole and make it firm. Add a little more compost on top, but not all the way to the top (or when you water the pots the water will fall out the sides)
Add a label to your new seedling so you know what they are as they grow.
Depending on how dry your soil is you can give a very light water, don’t use a big hose or watering can as it will squash your little seedling. If you don’t have a small watering can, I have a haws small one* that is perfect for seeds and seedlings, use an old water / fizzy drink bottle with holes poked through the lid.
And then place in your greenhouse if you have one (depending on the temperature) or back on your window sill if it’s still too cold out.
Outside temperatures and seedlings
If your seedlings have been on a nice warm sunny windowsill, they won’t cope with going outside with a major temperature drop.
If you have a greenhouse, cold frame etc that is heated by the sun and you know there will be no more frost you can put them outside. But what you don’t want is a big jump in temperature.
You can keep them inside in a cooler spot, you still want them to get light but you also want to get them used to the cooler outside temperature.
Watering your seedlings
Don’t forget to keep the soil damp, and don’t overwater them though, a little and often is better than drowning them!