Tips To Ripen Tomatoes on the Plant
Towards the end of the season, you probably have some wonderful looking trusses of tomatoes on your plants … the only thing is, the tomatoes are still green! Here are a few tips to ripen tomatoes both on and off the plants.
If the tomatoes on the lower trusses have reached their full size but are taking their time to ripen, there are a number of things we can do to help the process along.
- Reduce nitrogen and increase potassium (potash). Too much nitrogen can delay ripening.
- Remove all side shoots and stop the plants by pinching out the main growing stem – on tall varieties.
- Remove all flowers or very small tomatoes that won’t reach full size before the end of the season.
Tomato Plant Stress & Forcing
Stressing tomato plants can make tomatoes ripen more quickly. This can be done by:
- Reducing the watering frequency
- Cutting some of the roots by sticking a trowel into the soil about 4 or 5 inches from the stem base – a bit extreme maybe, but it can work as a last resort at the end of the season!
- Removing Leaf branches up to the ripening truss
- Trim leaf branches so that energy will be directed towards the fruit
- Removes tomatoes that are just starting to turn colour
Professional growers often use a “forcing solution” to speed-up the ripening process. One such solution is GHE Ripen. It gives the plant a strong signal that it is coming to the end of its life. The plant reacts by speeding the ripening process, in a last effort to reproduce.
How To Encourage Picked Tomatoes to Ripen
This is a lot easier … all you need to do is to put them into a large bowl with a ripe banana or other very ripe tomatoes. The ethylene gas that is produced by ripe fruit encourages the unripe tomatoes to ripen.
Placing them in a paper bag with ripe fruit has the same effect.
Avoid Blight
There is not a lot we can do about blight once it gets established but taking preventative measures can help – especially if we know that blight is likely to appear in wet conditions as temperatures drop at the end of the season.
However, we still need to look after our plants towards the end of the season by removing old leaves and keeping good air flow around the plant – especially at the root base.
A Flush Through
Give plants growing in containers and grow bags a good flushing with plain water to remove any nutrient build-up in the soil.
Then feed at recommended full strength (plus a little extra) to encourage ripening.
Derek Warren
Hi Nick,
I’m growing 5 roma toms in bottomless pots in my greenhouse in Salford / Manchester and not one of the little darlings have shown any sign of ripening do you think they will ripen “it’s getting late” or will it mean jars & jars of green tomato chutney.
Here’s hoping
Derek.
Nick
Hi Derek, I’ve always found that Roma toms take a bit longer to ripen than many other varieties because of the amount of flesh content. The benefit is that they have a longer shelf life and will eventually ripen before they go soft.
Nick
Rob
Thank you Nick, I am enjoying a spectacular crop of greenhouse tomatoes after putting into practice everything I have learnt from your newsletters. I use ring culture and feel the use of your root aeration system (perforated overflow pipe) is especially beneficial.
This year, I fed half of my plants with Tomarite (plus a pinch of dried milk powder) and half with Chempak. I could find no discernible difference between the two feeds….. except price. Chempak will be my feed of choice for the future. I had not heard of Chempak until I came across your newsletter.
Every year, I grow a single plant of a previously untried variety. This year, I tried Black Plum. The fruit eventually ripened into the toughest, thickest-skinned, blandest, most tasteless tomato I have ever eaten!
With regard to ripening, I have in the past draped banana skins directly over the lowest trusses in order to get the ripening process started. More recently, I have taken to stressing the plant around ripening time by following your advice on branch removal – i.e. removal of branches up to the first truss – then removal of middle branches further up the plant if there are three branches between trusses. This seems to kick the plants into action.
Thank you again. Regards, Rob.
Nick
Hi Rob, Thanks for your interesting email and I’m pleased that you have found the newsletters helpful!
I have not tried Black Plum but it sounds a bit like Indigo Rose – looks great but is hard and tasteless – that’s another variety on my “must avoid” list!
Regards, Nick