Tomato blossom end rot and other tomato tips.
Suburban Sue

Tomato blossom end rot and other tomato tips.

In the greenhouse tomatoes are beginning to ripen - smaller varieties only. I discovered this morning a small cucumber making a go of it my first ever. I got nothing on my cucumber plants last year despite tickling the flowers with a fine paintbrush.

Tomatoes in greenhouse. Variety Red Cherry

In past years I have had issues with tomato blossom end rot. Disappointing when you actually have nearly produced some tomatoes. It’s not a disaster if you get it - just remove the affected fruits and adjust your watering regimen. What I hadn’t realised until I looked further that it is a watering issue which means calcium, of which there is plenty in the soil, doesn’t get to the furthest parts of the plants, which affects the uptake of water in the tomato cells. 

Remedy is to keep watering regularly - more when the weather is hot - and also check when it is windy as water loss from the leaves is higher then. If the soil is dry, water before feeding so the feed will not be trapped in the soil but available for uptake by the plant.


I was also thinking about this with regard to other advice I’ve been given such as taking off the lower leaves of tomatoes to let in the light and allow the fruit to ripen. In my mind it seemed counter productive as surely the tomato needs light on the leaves to grow? Providing it has some leaves, by the time fruit has set it will be putting its energy into the fruit anyway.


Another way of reducing water demand by the plant is to make sure you nip out the sideshoots of cordon grown tomatoes. This will reduce the amount of water the plant needs to keep the leaves and stems supplied.


In my greenhouse, for purely practical reasons, I have trimmed the larger tomato leaves back by half, so I can walk down the greenhouse but this will also have the effect of reducing water loss through transpiration as well as giving more light to the fruits.


So here’s to a better harvest!