Transplanting Tomatoes and Pot Sizes

Pots for SeedlingsIt is common practice to transplant seedlings into 7,6cm or 3inch pots for their first home.

This is fine for a few weeks (depending on temperatures and light levels) but they will most likely need to be potted into a larger pot before they can go into their final position in greenhouse or outside in the garden.

The problem is, the earlier that seeds are sown, the longer that the small plants will need to be inside, in the warm, before they leave home and depart to the greenhouse or garden!

Ideally, their second pot should be around 5 inches, then after, they are planted into their final position which means, in my part of the world, a place where temperatures are too low until at least the end of May.

Because I sow early, I have often have to pot for a third time into a larger pot than a 5 inch before planting in the final position late May or early June. If I don’t do this the plants become root-bound and growth can be become stunted.

The following video is one from last season where I had five plants, each receiving different food to test which types of food produced the best results. Unfortunately, I had to wait ages for the flowers to set so the experiment didn’t quite work as I had planned!

Who says that naming your tomato plants is a bit daft!!!

So you may ask, why sow so early?
That is a question I ask myself – especially when I’m tripping over tomato plants indoors in April and May!

Sensible people will, of course, resist the temptation and wait until around two months before their last frost date before they sow their seeds and not have the problem of potting-on for a third time!

However, if you can cope with the extra work and time involved when starting your seeds early, the reward is an earlier crop – that’s if the plants don’t suffer from the low light and low temperature conditions!

6 Responses

  1. Beverley Lloyd
    | Reply

    Hi, I have potted my tomatoes on in their final large pot from the 3” one. Is this wrong and if so why ?
    Thanks for any advice

    • Nick
      | Reply

      That sounds fine, as long as the plants aren’t exposed to frost overnight.

  2. Dave Brown
    | Reply

    New to tomato growing and indeed gardening (fledgling of less than a year) so I find this website most educational.

    I started off my first seeds mid March in 3″ pots and they are just peeking through in the kitchen. Got some 5″ pots ready for the ‘potting on’ then they will go in the greenhouse when ready. I have bought a few sets of ‘ring culture’ type pots and will be putting those on top of growbags.

    I will let you know how I get on.

    Thank you again. Regards


    • Nick
      | Reply

      Hi Dave,
      Sounds like you are doing very well – look forward to hearing how you get on.

  3. Shirley Walke
    | Reply

    Hi – I didn’t sew my tomato seeds until April last year and they didn’t do that well. I did hear though that generally tomatoes didn’t do well last year at all. This year I have sewn my seeds early so will be interested to see how well they do. Incidentally, I have had a go at harvesting seeds from some delicious tomatoes someone gave me last year. They have all germinated and are looking quite healthy. I have no idea what they were but fingers crossed they taste as delicious as the toms they gave from.


    Shirley Walke

    • Nick
      | Reply

      Hi Shirley,
      I know that many gardeners struggled last season to get a good crop – especially in those areas where there was a lot of rain.
      It’s always fun (and good value!) to save and sow your own seeds. Seeds saved from last season are vigorous too!

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