Tomatoes not turning red and ripening? Here is what to do

Here I set out 5 easy techniques to help you bring your tomato growing efforts to fruition when your tomatoes are not ripening on the vine. But first let’s answer this question:

Why your tomatoes are not turning red

Even if your tomatoes are big, they may not be turning red. There are 3 main reasons why tomatoes fail to ripen and turn red:

  1. Too much heat: tomatoes love heat, but not too much. Prolonged extreme heat stresses the tomato and causes it to to stop developing;
  2. Too much cold: tomatoes stop cease producing the carotene necessary for ripening if temperatures get too low, as often happens at the end of the season;
  3. Too much feeding and watering: tomatoes that are too well pampered just keep putting on fresh new growth instead of diverting their energies to seed production through ripening their fruit.

Note this applies to cherry and roma tomatoes that are not turning red, as much as to any other green tomatoes.

The tomato grower’s story

You’ve spent all summer carefully nurturing your tomatoes.

You’ve sown the seeds early in Spring, dreaming of eating juicy ripe tomatoes with fresh bread, mozarella and your lovely home grown basil.

You’ve seen them germinate and pricked them out into pots. You’ve grown them on, watered them and potted them on again.

You’ve improved your soil, planted them out in the garden or into a growbag in your greenhouse.

You’ve watered them, weeded them and fed them once they set fruit.

You’ve worried about the brown or purple tinges you might have seen on some of the leaves, googling to see what it might be.

You’ve pinched out the sideshoots, including the ones that appear out of nowhere at about 60cm long that you somehow missed a week or two earlier.

And you’ve watered and fed them some more.

If truth be told, and it a little bit like your plants, you’ve probably got a little bit stressed on those hot days when the plants are wilting and it looks like you’re going to lose them. And you’ve been very relieved when they regain their strength and perk up in the cool of the evening.

And with the plants laden with green fruit, you’ve rejoiced at the first sight of an orange blush on one of the tomatoes, and you’ve checked on its progress every day.

And finally, on a day that it seemed would never arrive, you carefully picked your first tomato.

You hold it carefully in your hands, you feel its warmth and you smell its unique tomato aroma. You carry it triumphantly inside to receive the acclaim that it, and you, deserve.

Then they come thick and fast. There are tomatoes ripening day by day.

It’s tomato salad, tomatoes in your sandwiches and maybe even fresh tomato juice with your vodka.

Until suddenly they are not coming so thick and so fast.

The days are getting shorter, the heat of summer is dissipating and there are a still a lot of lovely green tomatoes that are not ripening on the plant.

So you start to worry that, with your tomatoes not turning red, a lot of your hard work and effort over the months is going to have gone to waste.

What to do if your tomatoes are not ripening or turning red

20 minutes 20 minutes.

Take these 5 steps to get your green tomatoes turning red. These techniques apply to all tomatoes, including cherry tomatoes that are not ripening:

  1. Stop the plant

    When your tomatoes are not ripening on the vine, you first need to stop the plant putting any more energy into growing, so that all the energy goes into the existing fruit. This means you need to pinch out or cut off the plant at the top growing point, so that it won’t get any bigger. You can see where I have done that in the picture below.

    Also, cut off any flower trusses that have not yet set fruit, or have only tiny fruit, because these will not be able to grow enough in the time that is left in the growing season.Pinched out top of tomato plant

  2. Pinch out side shoots

    Tomatoes are vigorous plant. So despite all your best efforts, side shoots keep coming back. You should have been pinching out side shoots as the plants has developed, but now is the time to keep a keen eye on this and keep pinching them out. This, again, is aimed at making sure the energy goes into ripening the fruit.

    You can see a new side shoot developing in the picture below, even though it is late in the season and I have pinched out shoots from that spot before.
    tomato side shoot

  3. Cut back the foliage

    You need as much light as possible to get to your tomatoes. It is really warmth that ripens the tomatoes, rather than light. But as the strength of the sun weakens in Autumn, it’s best to get as much direct sunlight on to the fruit as you can to maximise the amount of warming they receive.

    Now that you don’t want the plant to grow any bigger, it does not need so many leaves for the photosynthesis that fuels its growth. So, in late August or early September (Northern hemisphere), you can cut off half to two thirds of the plants leaves, making sure especially to take off those leaves that are preventing light and warmth getting to the fruit. Later in September/October, you can take off more or less all the leaves.

    This picture is from early October and you can see that I have removed most of the leaves from these plants now.
    green tomato trusses

  4. Put them in a bag – with a banana

    If all else fails and the tomatoes are not ripening on the plant, you can place the unripe fruit in a paper bag with a banana in a drawer or other dark place. Bizarre as it sounds, this works because the ripe banana gives off ethylene and ethylene promotes ripening in fruit.

    This works best with fruit that are showing signs of starting to ripen (i.e. a hint of orange flesh). Also, check regularly for any signs of rotting and remove any fruit that are starting to rot.

  5. Hang the plant upside down

    One final method (an alternative to the banana in the bag trick) is to pull up the plant and hang it upside down somewhere warm dry and away from frost (e.g. a garage). You probably won’t get all the fruit to ripen, but in this way you can harvest a few final fruits of your labours.

So there you have it. Don’t let all your efforts go to waste. Try these techniques for ripening your tomatoes.

And if you’ve got any other tips, let us know in the comments.

What you need

The most important tool that you need is a good pair of secateurs for cutting back the foliage and stopping the plant.

I only ever use Felco secateurs, which in my experience have proven to be the best and most reliable secateurs around. I use the Felco number 2 as it is a good all-round secateur.

US Buyers

Sale
FELCO F-2 068780 Classic Manual Hand Pruner, F 2
  • Comfortable, lightweight, sturdy aluminium alloy handles
  • High quality hardened steel blades, forged aluminium alloy handles, wire cutting notch
  • Anvil blade with sap groove, rubber cushion shock aborbers
  • For a medium to large hand, right Handed; the handles have a non slip coating
  • Lifetime guarantee, all parts replaceable
Sale
Felco Pruning Shears (F 7) – High Performance Swiss Made One-Hand Garden Pruners
  • The Felco 7 Orcharding and Garden secateurs is best used for cutting tasks in your garden. It is best suited for twigs and plants with a diameter not larger than 2.5 cm.
  • The box contains the garden and orcharding secateur that is equipped with a wire cutting notch and a sap groove.
  • The shear provides a clean and precise cut for twigs and other plant parts up to a diameter of 25 mm.
  • The one-hand pruning shear has an ergonomic design through a hand and wrist protection and an optimisation of the force by a revolving handle. Furthermore it is equipped with a non-slip coating.
  • The sturdy handles are made of forged aluminium whereas the blade and the screw-mounted anvil blade are fabricated out of high-quality hardened steel-
Sale
FELCO FELCO322 Model 322 Snips, Red
  • Carbon steel blades with chromium coating to prevent corrosion and make blade crossing smoother
  • Blades with sap groove
  • Straight blades with rounded ends for precise cuts without damaging the fruit
  • Polyurethane shock absorbers to reduce muscle tension
  • Stainless steel pin spring for smooth movement, which reduces muscle tension + Pressed blackened steel handles for optimum durability

Last update on 2023-01-27 / Affiliate links / Images from Amazon Product Advertising API

UK Buyers

Felco Number 2

Felco Professional Model 2 Secateur

£69.95  in stock
Harrodhorticultural.com
as of January 25, 2023 10:49 pm

The Felco model 2 bypass secateur is a popular and high quality product, used and highly recommended by gardening professionals. It features:

- comfortable lightweight, easy to grip handles,
- a hardened steel blade with a wire cutting notch,
- riveted anvil with sap groove to allow plant fluids to drain away
- a toothed centre nut mechanism which easily aligns the blades for a clean precise cut
- a rubber cushion shock absorber that protects the wrists.

Felco No 2s carry a lifetime guarantee and all parts can be replaced, so it is easy to see why these are the secateurs of choice for many horticulturists and serious home gardeners.

21.5cm/8.5" overall length can cut stems up to 2.5cm/1" in diameter.
Weight 240g/8.5oz

Felco Essential

Felco Essential Secateur

£45.95  in stock
Harrodhorticultural.com
as of January 25, 2023 10:49 pm

The Felco Essential Secateur is the entry level secateur made by Felco, the renowned Swiss master secateur makers.

Designed for larger hands, these secateurs are suitable for all general pruning and cutting work.

This model features an ergonomic grip made from high tech composite materials for comfort and a finely machined alloy professional cutting head, for efficiency of cutting.

Measures 21cm (8.25”) in length
Weighs in at only 190g (6.7oz)

Learn more about growing edibles

Check out these posts for more on growing your edible plants:

How to grow zucchini – this is the ultimate guide to growing this delicious squash.

How to prune your tomatoes and pinch out your tomato side shoots.

How to get the best out of your basil plants.

Here is how to prick out your tomato seedlings.

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3 thoughts on “Tomatoes not turning red and ripening? Here is what to do”

  1. Pingback: What are weeds?
  2. Thanks! It’s hard to find answers to why our tomatoes won’t ripen. But although most of them are turning red, the cores are hard and the tomatoes are not soft and juicy so we left them on the vines too long, I think. I’m trying the banana trick for sure!!

    Reply

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