Are your tomatoes and fuchsias out it the garden or under cover, Pennyplant? If they are in the garden the leaves are probably going white because it's been too cold for them. It's rather early to have them outside, unless you live somewhere really mild.

The accepted time to put tender plants out is mid to late May, after you've spent a week or two hardening them off by putting them outside for increasing periods during the day and bringing them indoors at night.

I'm glad this question was raised...my fingers have been burned with this one - thanks Beattie - a lot of mine are white - OH asked me what it was the other evening and I said (confidentally ;-)) it was Seagull pee (but quietly wondering just as much as him what the heck it was !!) - as it turns to white on pavement - what am I like eh ?

Toms DO need full sun don't they ?