Tomato seed failure

[Startoftheyear2025]

I’ve grown tomato plants from seeds before but this year they seem to have stopped growing for no obvious reason. Anyone know why that might be? I planted them a while ago and they sprouted but have now stopped growing at about 2 inches high.

Is it the same variety as usual? I started off a few different varieties at the same time in March and some are a foot high while other varieties a few inches.
Perhaps try potting on into bigger pots burying the stems deep and maybe a bit of liquid fertiliser.

Thanks. I’ll try that.

Mine are about 5 inches high, I'll be repotting them this weekend.

Are they new seeds from a packet or ones you saves from last year?
Were they hybrid plants last year?
If they germinated, was the soil too dry/wet? Were the plants kept too hot/cold? Poor grade of soil?
Could be so many things.

Ooh thanks @JDM625they were boring seeds bough from my local garden centre. No obvious reason for them to fail to grow.

Where have you planted them out?

I suspect the compost wasn't great quality and the plants have run out of nutrients. Repotting them might do the trick.

I would feed them. I have found it a difficult year for all my seedlings although my tomatoes are doing okay.

I am beginning to wonder about the compost. My tomatoes are doing ok now but initially the leaves had a bleached look and didn’t look very healthy. I’ve been potting up and adding liquid feed but it’s the first I’ve seen leaves looking like this.

Compost is awful, it dries out too quickly and ends up looking like fluff. I've bought a bag of Jack's Magic and although has some woody bits in it it's lovely and fine so I've switch to that for seeds.

I think it's very much to do with the compost. I do find the modern peat free composts incredibly difficult to keep properly moist, especially in cellular trays. The top can look fine and feel damp but underneath it's as dry as dust, and if it's too dry the roots can't absorb any nutrients properly.

It's difficult to get such dry compost to absorb water, sometimes it's easier just to repot into compost that you know is properly watered all through.

I like Jacks Magic too, the Melcourt Sylvagrow is very good but it's expensive. I don't think it's worth the extra money tbh.

I'm a pretty experienced tomato gardener, and mine have done the same thing this year!

I also think it's the compost, and I've bought new/different and I'm repotting all mine today.

I don't really know much about gardening but I always use grow bag soil in my tomato pots. I have no idea if it's different to other compost.

I have had one delivered overnight by milkman to do mine today.

Mine have also failed, garden centre guy says the peat free compost is the problem.

I buy extra compost to keep until the next year and it's really nice and rotted down and whatbive planted in it has done well. Not much help for this year!

Thanks all. I’m sure it was the compost. Very helpful.

Don't feed. Compost needs to be mixed with something like vermiculite and a bit of John Innis or clean shop bought topsoil. The seeds have all the food they need at this stage so it's important that you let the roots get well established, and feeding will cause more green growth and weak roots. I don't feed my tomatoes anything until the trusses have set then I go in with a very dilute potash heavy liquid feed. Chichen manure is a brilliant all round fertiliser.

If you've got any molehills, use that mixed with vermiculite or perlite. You can sterilise the soil in the microwave covered obviously.

Thanks everyone. I’m sure it was the compost so I’ll repot them. Thanks.