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Help! Seedlings Dying

Hi folks,

I'm hoping someone can help me. I started growing veg about 4 years ago and have been pretty successful for a novice. I have grown loads of tomatoes (no greenhouse, just in pots), runner beans, corgettes, carrots (though tiny!), chillis, brussel sprouts, chard, etc. Our old house had a big garden and a conservatory, I used to grow the seedlings in the conservatory and then move them out to the garden when ready.

Beginning of last year we moved into a smaller house with no room indoors to germinate seeds, but I was still determined to continue growing veg, again successfully using a seed tray outdoors and in big pots and trays after.

This year I can't seem to grow a thing. image Not even my usually successful moneymaker tomatoes. The weather is better (dryer) this year than last. Only about half the seeds I plant germinate, and the ones I do get about an inch high and then keel over and die.   Thinking it wasn't warm enough I built a 3 frame "mini greenhouse". Didn't make any difference.   I then though thought that perhaps they were getting too hot in the "mini greenhouse" in the seed tray with the plastic cover on top. I removed the plastic cover, now nearly nothing germinates. image

The only other thing I can think of is I have bought no new potting compost this year as I had half a bag left over from last year, but I have about 10 pots so spread this about. I can't remember if I used the bag compost in the seed trays or robbed it from other pots.

A long post I know, so sorry about that. So is the likely cause the compost, trying to germinate outdoors or overheating in my "mini greenhouse"?




  • CeresCeres Posts: 2,691
    This may be of help to you.

    Sounds as though you are suffering (or rather your plants are) from a plague of damping off. Either that or you have tiny larvae in the compost that are eating the roots of your baby plants. It is very frustrating when this happens but don't give up hope. Start again with new compost and ultra clean pots.
  • PalaisglidePalaisglide Posts: 3,414

    Jon, Old compost for seeds is a no-no, seed compost needs to be sterile and old stuff will not be. I have used old compost though steamed it first or at least put it in a bucket and poured boiling water on it, a last minute fix not really recommended.

    Seeds need a constant temperature very hard to control without a place to keep an eye on them it varies from 8C to 20 C depends on the seed though most veg will be the lower temperature, they will grow in outside seed beds although not until June in this area the Northeast Ne'er cast a clout till May is out is a truism up here.

    Seeds will germinate in sand though my mix is one third sand one third grit and one third sterile compost then at two true leaves pot on to half compost half sand and grit mix, like babies they need to be weaned onto hard food, the old compost could be too rich.

    If you have a South facing brick wall that will take in the heat and give it back at night then put your seed trays in a box next to the wall and cover with some rain proof material, you will need to open and close the lid according to temperature.

    Without a greenhouse or an inside windowsill it is hard work and as with all gardening worth it in the end. Hope this helps.


  • John HardingJohn Harding Posts: 541

    Good advice from Frank. I wash all my pots, seed trays etc in a strong solution of Jeyes fluid as soon as the plants/seedlings are potted on and then wash everything off in clean water and dry them off before putting them away or re-using them. Always use a seed compost when sowing seeds and when using a cold frame or Greenhouse make sure you have good ventilation during daylight hours as poor ventilation contributes to damping off. Also remember to clean and disinfect any tools & equipment you use when handling plants/seedlings as spores can be transferred easily to other healthy plants causing them to fail too.

    Another problem you might be encountering is soil borne pests such as slugs, snails, leather jackets, vine weevil grubs etc. treatments are available for these and if you can identify which ones you have (if you have any) ask someone at your local garden centre for advice. Taking a pot with you to show them will help them identify your problem.

  • HealisatHealisat Posts: 6

    Thanks for the swift replies folks, really appreciate it. I've(hopefully) included a couple of pictures of the cold frame and the dying plants inside.   So it sounds like poor compost or dampening off or a combination of the both.   I've just bought 2 bags of Miracle Grow.   Sounds like I need to ditch the old stuff, sterilise the seed tray/ pots and start again.   Thank you so much for your help.   I'll let you know how I get on. image





  • HealisatHealisat Posts: 6

    Just a quick note on the top pic so you know what is what. At the front is a dead tom, seed tray right is chilli peppers, you can't really see but they sprouted and died, seed tray left is toms about 3 weeks old, think they should be bigger by now, next row dead courgettes, and at the back 3 onion and 1 tom, all about 6 weeks old, should definately be bigger.

  • PalaisglidePalaisglide Posts: 3,414

    Jon, that looks a perfectly viable set up to me and your seeds should set OK, Try using John Innes type seed compost, (that by the way is a recipe used by other makes of compost) new compost should be sterile, if not complain, I have and won.

    At night if it is cooling fast use blanket or bubble wrap as extra cover and remove next morning when things warm up, those first weeks of effort will pay off in healthy plants.


  • HealisatHealisat Posts: 6

    Thanks Frank.   I'm going to have to stick with the Miracle Grow now I've bought it, else my Partner will give me a slap, lol.   But I'll buy John Innes in the future.   I work in Chorley throughout the week and return back home to Nottingham at the weekends, so unfortunately I'm not about anymore for daily care. My Partner is happy to keep them watered, but I don't think she'll do much more pampering to the plants.

    I have noticed now I have emptied the pots that there are woodlice in them, will they eat seeds/young plants?   Also, a weeks ago when I took the seed trays out of the main try, the tray was riddled with ants, I sprayed it with bug killer and rinsed it out with water.   The ants haven't returned, but could they also be a factor.

    Sorry, I'm feeling a bit silly. Anyway, I have emptied all the pot and am pouring boiling water on them.   Hope I am doing this right.   Shall I put a cap of disinfectant



    in there as well? And rinse after obviously.

    Thanks again.

  • John HardingJohn Harding Posts: 541
    I'd use Jeyes fluid noting the directions on the tin. Also check if the Miracle Grow compost is for seeds - if it's not you may well be wasting your time (& money) again. It's getting a. It late to sow tomato seed now so buying some healthy plants from a GC may be a better plan for this year.
  • HealisatHealisat Posts: 6

    Thanks John and for your earlier post.   The compost says for large seeds, seedlings and cuttings, perhaps not good for tomatoes.   I bought a chili and green pepper plant from a G/C a couple of weeks ago and those are doing fine.   Plus my runner beans I grew from seed are doing good too, except one that was completely eaten within a couple of days by snails, but oddly they didn't touch the others.   It would be a shame if I had to buy tom plants as I've always had good results for the last few years from seeds, but I might have to concede this late in the year.

    I might have to get some Jeys, but I have some generic disinfectant I'm going to use in the meantime. Again, many thanks for your advice. image

  • PalaisglidePalaisglide Posts: 3,414

    Jon, ordinary domestos is what I use, cannot stand the smell of Jeyes, as long as you rinse the utensils well after. Buy a bag of washed sand and mix your seed compost half and half for now this will reduce the feed potential. The advice to buy some Tomato plants is good it is late for sowing seed, other Veg can be sown in sequence, tomato's need the early summer sun and warmth (if we get any).

    You show me a gardener and I will show you some one who has made mistakes, we all do it so worry not. If you cannot move that frame then cover the base in plastic and pebbles if you have any. Not being able to get to your frame during the week is not good, if you cannot train your partner with a whip and chair then remove a glass away from the plants and away from the prevailing wind, that should stop over heating.

    Hope this helps Frank.


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