We’re growing three tomato varieties this year. In the greenhouse we have Ailsa Craig, a well-established standard sized tomato, and Sweet Million, a cherry tomato. Outside in pots we’re growing Sweet Aperitif which is another cherry variety.
The greenhouse tomatoes are planted in a soil border. This is enriched with garden compost and chicken manure pellets. Two years ago I shovelled out all the old soil and replaced it to try to eliminate any build up of fungal spores or bacteria. As much as possible I try to rotate the tomatoes, aubergines, peppers and cucumbers that share the space.
This year the greenhouse tomatoes are glowing with vitality. Good, healthy, green foliage, and large fruits setting on all the trusses. Some are just beginning to ripen and I’ve been removing the lower leaves to allow more air and light in.
However the three plants outside are looking very poorly. I potted them up in all-purpose compost enriched with John Innes and almost immediately their leaves started to mottle and shrivel. The plants are skinny and tall. I thought it was a magnesium deficiency. This is very common in tomatoes if they are over-fed with potassium-rich fertiliser. The potassium inhibits the absorption of the magnesium. I had only fed them once so I didn’t think it was this but I applied some Epsom salts anyway. It had no effect. Then I thought maybe it’s potassium deficiency so started to give them a dilute feed but again that did nothing. The plants were flowering, the fruit setting and they’re beginning to ripen. If it was a severe nutrient deficiency I think the fruit would be deformed so it’s all a bit of a mystery. It could also be Tomato Mosaic Virus – a nasty disease – but again I think the fruit would be affected.
Conversely I haven’t fed the greenhouse tomatoes at all – all they have had is chicken manure pellets forked into the soil a month before planting out and they are thriving.