Swansea. West Glamorgan., Wales

I have 2 Tomato plants that were given to me by a friend. I don't know what they are, but I do know they were grown from seed, as the lady who gave them, grows from seed every year. I'm guessing gardeners delight or ailsa craig. I've put them both in a growbag, in the green house, but I noticed day before yesterday, that on one of them the leaves had started to curl. I thought it needed water, so I watered them, and they looked like they were ok. Yesterday i went to water them and noticed that the ones leaves were still curling. I've checked the underside of the leaves but there is no sign of bug damage, and the leaves are still green (no discolouration at all) and apart from the curling, the leaves are fine. This tomato plant is actually flowering. Why is this happening, and only to the one plant, the other plant is healthy, when they're in the same growbag. It's only the top leaves that are curling, the rest of them are fine. As you can see from the pics, it's only the top of the plant that is suffering, and if I've uploaded this correctly, you will see that the other plant next to it is fine. Thanks for looking.

• 15 Jun, 2011