Hi, my tomatoes have developed rot at the bottom of the fruit. My other plants appear to be okay. Can you please advise how to stop it affecting my tomatoes? Matt.
The problem is blossom end rot which commonly affects tomatoes, capsicums and courgettes. It is not a disease but a physiological disorder and can't be spread from plant to plant or from fruit to fruit.
See below for causes of blossom end rot and ways to help prevent it:
- Irregular, uneven watering. Water plants consistently and regulate the watering depending upon the weather conditions.
- Tomatoes growing in containers (or planter bags) have more chance of drying out - one big water a day is preferable to two light waterings. Take care not to wet the foliage too much. Use SaturAid for container grown tomatoes to ensure that water is evenly distributed through the pot and the potting mix remains moist between waterings.
- Tomatoes planted early in the season when temperatures are cool are more susceptible to blossom end rot. Early fruit may show signs but later developing fruit should be fine.
- Tomatoes can also develop blossom end rot due to a lack of calcium and magnesium. Use a fertiliser low in Nitrogen (N) and high in phosphorus (P).
- As tomatoes grow very rapidly over a short period of time, make sure you feed them regularly, if using a liquid feed do it every fortnight.
- If you are growing tomatoes in a glasshouse increase the ventilation as high humidity can also contribute to blossom end rot.
Tui Organic Seaweed Plant Tonic is a seaweed based tonic which is great for tomatoes.
The good news is if you get the fertiliser regime right and water consistently the blossom end rot will go away. Remove and affected fruit to encourage more fruit on the plant.