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I have grown tomatoes in my greenhouse for the past 2 years and on neither occasion have they turned red.  I have used different types each year.  Can anybody advise what I am doing wrong. I water and feed them and take out the shoots and there are plenty of tomatoes on them 


  • Did you start them off too late?
    Does it get too hot in there? When it's too hot they stop growing.
  • Pete.8Pete.8 Posts: 10,306
    Once the fruits are fully formed they will start to turn red.
    If the temperature is above 30C or below 12C for a period of time they won't ripen until temperatures fall to between 12c and 30c.
    If yours aren't ripening then I can only think that by the time your tomatoes are fully formed temperatures are too low for them to ripen.
    Some varieties take a lot longer to ripen than others.
    What variety are you growing?

    I start mine from seed in the 1st week of March.
    This year Rosella was the first to start to ripen about 3 weeks ago.
    Now I have a few Shirley that are ripe.
    Rose de Berne are still all green, but I usually start harvesting them around mid-August.

    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • Also, you can remove a lot of lower leaves for the sun to get to them
  • AuntyRachAuntyRach Posts: 4,989
    edited August 2022
    Once I see plenty of green tomatoes I take off about half of the leaves so the sun can do its work, like @Penny_Forthem said. 

    I am really pleased with my short bush ‘minibel’ ones this year. I’m not sure I’ll bother with many tall cordon ones again. 
    My garden and I live in South Wales. 
  • DovefromaboveDovefromabove Posts: 83,923
    Do your tomatoes show the change from dark ‘acid’ green to s softer green that is the start of the ripening process?

    How long are you allowing for your tomatoes to ripen?  

    Mine are outside and only my little cherry toms are beginning to ripen at the moment. All the others are still green and growing. I usually pick the last of my ripe ones before we go on holiday mid September … then I cut the remaining trusses to ripen indoors while we’re away. 

    Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.

  • JennyJJennyJ Posts: 8,865
    Mine don't generally start to ripen until August (outside), and go on often into October. I pick whatever's left to ripen indoors when the first frost is forecast.
    This year Sungold is early (been picking a few most days for the last two weeks). Blue Bayou are ripening but they're bigger than I expected and slow to turn on the undersides, so I've picked some and put them upside-down on a sunny windowsill, which seems to be working. The first Rosella are just starting to show some colour. Gardeners' Delight and Yellow Pear are still all green and looking like it'll be another couple of weeks before any are ripe.
    All sown mid-late April because I don't have a greenhouse and they can't go outside here until the end of May.
    Doncaster, South Yorkshire. Soil type: sandy, well-drained
  • thanks thanks for all the comments and will follow the advice and see how I go 
  • FairygirlFairygirl Posts: 52,134
    I only grow cherry types [including Sungold]  and they're undercover, although I stuck the extra ones, that have been in the house, outside a few days ago once the night time temps went up again. I don't get any ripening until end of July/beginning of August here. The trusses start setting around mid to end of June. It takes around 6 to 8 weeks from those trusses setting, to have them ripening steadily, and mine will continue through to the end of September no problem. It will depend on the variety though.
    If you're in a very hot area, and they're inside,  it's important they have plenty of ventilation too, because it inhibits them if too hot, as already said, but it sounds as if they're doing ok. If you're in a much colder part of the country, it'll take them longer to start ripening, so you may find they'll need some help later in the year.
    As @Dovefromabove says, one they're turning a paler green, they'll keep ripening as long as they have enough warmth, so don't worry too much just now if they're otherwise healthy. 

    If you have a photo or two, that can also help with further advice  :)
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • It's a myth that the fruits need sun. The plants do, but not the fruit so don't go stripping leaves off.
  • @MikeOxgreen I think pruning lose leaves just helps to improve ventilation to prevent blight as well as make harvesting easier.. 
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