What’s gone wrong with my tomatoes?
Q I seem to have a problem with my tomatoes this year as they have developed black spots. Is this the same as the roses and is the treatment the same? Also, is there a sawfly that eats laburnum leaves?
Georgina Barham (via email)
A Bad luck! I suspect that your black-spotted tomatoes are suffering from blossom-end rot, a physiological disorder in which erratic watering, in which the soil or compost dries out between being very wet, can cause an imbalance in the uptake of calcium, resulting in fruits that fail to mature normally. Alternatively, but less likely, your plants are suffering from alternaria canker, bacterial speck or anthracnose, for which there are no remedies.
Sadly, at this late stage with blossomend rot, all you can do is water carefully and regularly, ensuring that the root area is evenly damp at all times.
As for a sawfly that eats laburnum leaves, there isn’t one. Caterpillars are the most likely culprits, but there are none specific to laburnum.
Admittedly, laburnum leaf miners, just a few millimetres long, that tunnel beneath the upper and lower leaf surfaces, feast on this tree, but they are too small to cause the damage described. If the problem persists and further leaves are eaten, I suggest that you spray the tree with Bug
