Tomato rescue bid

The leaves on my indoor tomato plants turned blue-brown before going yellow and falling off. Some of the tomatoes are ripening well, but others are not growing. What am I doing wrong?

Q: The leaves on my indoor tomato plants turned blue-brown before going yellow and falling off. Some of the tomatoes are ripening well, but others are not growing. What am I doing wrong?

A: The symptoms you describe suggest red spider mite. You may not have noticed this pest, but if you were to turn up the leaves and study their undersides, you would probably see a thin, web-like layer over the surface. If you view the leaves with a hand lens or magnifying glass, you would be able to see the mites moving about.
If the infestation is severe, the plants may not recover. However, with quick treatment, it might be possible to bring them back from the brink, at least to ripen a little more fruit. Begin by making their environment more humid. Spray the foliage from time to time with plain water when there is no direct sun, since the mites loathe moist conditions.
For a remedy, you have two choices. The most effective chemical control is with Bayer Garden Provado Ultimate Bug Killer, used as a spray. If you prefer not to use chemicals, the alternative is biological control. However, if the infestation is severe this late in the year, it may be too widespread to combat with predatory mites. Biological controls are available from such suppliers as www.harrodhorticultural.com or www.defenders.co.uk.