May 6

How do I know when it is ready to prick out/transplant/plant out?

We get the best of questions on our veg course at the allotments because we take so much for granted. One of the excellent things about working with adults is that they will ask the questions around the areas that you don’t explain. It is a really good question. Over time, experience will tell you that the plant is too small, too big or just right for the size of container you are growing it in. But, there are other things that you can judge by.

Roots and size of plant.

We sow the majority of our seedlings in modules for a variety of reasons. We know a plant is ready to go out when we start to see the roots coming out of the bottom of the modules.

The celariac below is just about right and ready to be planted out. Look at the size of the plants, the amount of roots coming out and when I pop one of the modules out, the roots in the compost. The plants are not touching each other and you can still see the sides of the modules unlike the lettuce seedlings in the previous pictures.

So, what about vegetables grown in pots? Well, the same principles can be used. Below is one of my tomato plants that could be planted out in my polytunnel now. It is a reasonable size in the pot and the roots are just starting to peep out of the drainage holes.

And finally. How do we know when to prick out seedlings?

Well, here the smaller the better. They only need their seed leaves. This means that their roots are not too big and difficult to get ino the holes we dib for them, we are also less likely to tear the roots as we tease them out. This will all reduce the transplant shock.

Brussel sprout seedlings ready to be pricked out. They are not big!

But don’t just take my word for it. In this article by Charles Dowding, scroll down and you will see a section on transplanting. Charles seems to judge his by the amount of time they have been in the modules – about 4 weeks. Dates on your plant labels help here. He is also trialling planting out when the plants are even smaller this year to see if that has an impact on growth. Tricky with all this rain and not too much sunshine.

Keep on asking those questions.