Potting on your seedlings

We are potting on our tomatoes but this process applies equally to other seedlings, peppers etc.

It’s time, our tomato seedlings are starting to look strong and healthy, but I’m very aware that they will soon be too large for the tiny little starter pots I gave them. If we allow this to happen, the roots will grow out through the pot and be cauterised by the air and the seedlings will begin to get leggy and long, instead of strong. We want strong roots because the plants are going to get tall and carry a lot of fruit and we need those roots to stabilise the plant, as well, obviously, as carrying water and nutrition to the plant. Also, leggy plants are much more susceptible to being accidentally snapped and broken, so we really want to prevent this where we can. This is why we move them on into larger pots.

Now I know some of you guys are growing tomatoes for the first time this year so you’ll be asking, “but Eli, how do we know when it’s time to pot them into a bigger pot?” So, here is my simple tip. It depends on how you have grown them. Cryptic, huh?

Ok, if you started them off in the tiny little seed trays like this,

once they have their second set of leaves, move them to a slightly bigger pot, like the little paper pots I have.

Once you have already potted on once and the seedlings are in nice little pots like these

let them grow a while, until they are 2 or 3 inched tall and starting to get top heavy. Then repeat but with slightly bigger pots.

My little pot making widget doesn’t make bigger pots, so I have a cunning tip – a paint tin!!! Yup I said a small paint tin.

Basically, for the next size up, I use a small tin of varnish, it’s perfect. So I use that as a mould for making the next set of pots. Like this.

So, before I start, I make sure to water the seedlings well and let them sit long enough for that water to drain. I do this because watering the plants helps the soil stick to the roots making them easier to handle safely.

If you want to have a go at making your own paper pots, I’ll link the blog and video on this down below.

So lets get repotting

Water the plants in advance and allow the soil to drain. The reason I do this is because this will help the soil stick to the plant roots making them less likely to dry out and less likely to be damaged.

Genius tip! Partially fill your new pot with soil, then place your original pot in there. Now fill with soil around your little pot. When you take your original pot out, it leaves a little gap for your seedling which is the perfect size. Pop your seedling in there and add more soil as needed and firm it in. TIP – if you are using these little paper pots, you don’t have to take the seedling out, you can “plant” the little paper pots and they will biodegrade in the soil.

If you have leggy seedlings, you can plant these deep. What will happen this is that the areas of the leggy stem which you have now buried will form roots. Meaning you get a much more stable plant. Fixing your leggy seedling problem.

Now you have basically just given your little plants a bit of a shock, so be nice to them, give them another good water and keep an eye on them for a couple of days.

You will pot on again once. For me, this will be when it’s time to pot into my quadgrow planters. If you are growing your tomatoes directly in soil then it will be when you move them to their final home. You will do this once the plants are good and strong and around 6 inches tall. If you are growing outdoors, this will be dictated by the weather, you don’t want to put your plants out into the garden until the weather is suitably warm and the risk of frosts have passed.

Make your own little paper pots