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Tomato first-timer - help!

cwrcwr Posts: 6

Hello everyone,

I should start by saying that I’m very new to all this, so apologies in advance if any of these questions seem silly!

I started some 'Moneymaker' tomatoes from seed in a propagator about 5 weeks ago (around 7th March). The seedlings sprung up in a week or so, and ever since then it’s been an exciting - if slightly anxiety-inducing - month of daily care and attention! 

When they outgrew the propagator and had grown two sets of true leaves, I transferred them into 9cm tall pots with all-purpose compost in. After a couple more weeks they’ve now started to outgrow those (roots poking out the bottom, now about 30cm tall with pencil thickness stem), so I’ve started hardening them off by putting them all outside for a few hours over the last 5 days, and I have repotted some into much larger pots. These ones in larger pots will sit on our balcony, and then I'm planning on replanting my remaining ones (in the photos attached) in the next day or two into a greenhouse that’s prepared at our allotment plot, with little beds handily all around the edge of the inside of the greenhouse.

I have started to notice that the bottoms of the stems are turning purple, the veins are purple, and the bottom leaves are starting to look purple both underneath, and on top around the edges.

I’ve read a lot about potassium deficiencies, cold temperatures, small pots, all sorts, and I don't know where to begin! 

So.. is this something I need to worry about? Or is it likely the tomatoes will sort themselves out once they’re in their bigger pots/bigger growing space in the greenhouse?

Thanks in advance everyone!! Chris 



  • GemmaJFGemmaJF Posts: 2,286
    Wow, your plants look amazing, I'm growing Moneymaker for the first time this year. I only just started them, so not showing yet.

    You hit the nail on the head, it is potassium deficiency. But not all that advanced, you have recognised it early.

    You could pot on and add bonemeal to the soil. 

    I think I would take the option of  starting with a good liquid feed, as it will have the right balance of other minerals to ensure potassium take up.

  • cwrcwr Posts: 6
    Wow, thank you so much For the kind words GemmaJF - that’s really reassuring! When it’s your first time, it’s very hard to know what’s normal and what isn’t I think. 

    In that case, I think I’ll start googling for bonemeal and some liquid feed. 

    Do you think I should start adding that as soon as I repot them into bigger pots/the greenhouse, or wait and see?

    thanks again, I feel a bit better already! 
  • GemmaJFGemmaJF Posts: 2,286
    You could incorporate the bonemeal when repotting, that would be ideal. 

    I would though try to find some liquid feed as soon as possible to reverse the effects of the deficiency.
  • bookmonsterbookmonster Posts: 399
    Ooh, my stupice have purple leaf undersides and I didn't think anything of it, will give them a feed
  • cwrcwr Posts: 6
    Great, thanks! I’ve ordered some liquid feed, so we’ll see how we go. Do show me your Moneymakers when they’ve grown a bit - would love to know how you get on with them! 
  • purplerallimpurplerallim Posts: 5,228
    It is still too cold to put tomatoes out, even in a greenhouse without heat yet. The marks could even be cold damage. When you re pot bury the plant right up to the bottom set of leaves, this will encourage new roots and make a stronger plant. For the size of plants those pots are far too small each needs a 10 to 15 cm pot.
    Hope this helps.
  • James271James271 Posts: 5
    Some great advice there on planting deep and feeding, and hardening off is the right thing to do. So for first timer sounds like you are doing very well. I would also say you are probably a good 2 weeks off putting in greenhouse, search for last frost online and this will give you a good steer for your area, your greenhouse is likely to only be 1 to 2 degrees warmer than outside at night, unless you have insulation or heating, so just take your time on getting them out don't rush as a cold night could just wipe them out. 
  • FairygirlFairygirl Posts: 54,358
    It's too early anywhere in the UK to put tomatoes out.  :/
    They need protection for at least another 6 weeks.
    No food - until the first truss is set. There's plenty of nourishment in whatever medium they're potted on into. Overfeeding just brings problems.

    The stems are fine - plant them up to the first set of leaves when potting on - as has already been said. Purple colouring is usually from cold, and if you've been putting young plants outside, that's likely to be the reason. Balconies are windy too - that won't help. Unless you have a heated greenhouse, sowing too early is always a problem.  :)
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • cwrcwr Posts: 6
    All really helpful, thanks everyone!  I’m down south, so it is slightly warmer climates in general (in the last week we’ve had some days at 25!) but even so, it definitely sounds like I’ve kicked things off a little early. (The purple stems/leaf bottoms actually started about a week before I begun “hardening off”, but it sounds like that’s probably partly the fact that my pots are too small too!) 

    I was originally reluctant to pot on to bigger pots as I knew I’d then need to take them out again for the greenhouse and I didn’t want to damage them, but frost sounds like the bigger risk by far! So, just to be sure I’m clear: advice is to pot on to slightly larger pots first, wait a couple of weeks, and then think about popping them in the greenhouse? 

    Thanks everyone, really appreciate it. And lesson learned for next year: sow seeds later! :-):smile:
  • FairygirlFairygirl Posts: 54,358
    Treat 'em mean, and keep 'em keen @cwr ;)
    Cold weather will check them, so it always comes down to your own climate, what facilities you have, and where you ultimately want to grow them. 
    If they're staying in a greenhouse, it's slightly easier, but always bear in mind that greenhouses get very hot during the day, and cold at night, so ventilation is also a big factor during the day, and if you sow early - you need some form of heat for overnight. Toms need a consistent night time temp of around 11 or 12 degrees,and when they're small, they need light more than anything. 
    Good luck with them - they look good plants, and Moneymaker is quite a forgiving variety too, so I'm sure they'll be fine  :)
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
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