Ah aphids. Got 'em and I'm after them every day. The neem did most in at the first application but flying aphids quickly replaced them. Excess nitrogen is probably my problem too. The only signs I know are lots of foliage and not much else. There are so many pitfalls that one has to be very careful. Too much lime will lock up iron and cause some yellowing at the top of the plants. Easily mistaken for nitrogen deficiency. So, in goes the nitrogen and along come the aphids. And that's just ONE of the pitfalls.

Too much nitrogen when growing tomatoes manifests itself as fast growing DARK green colored leafed plants. Little if any flowering may result as well. Too much nitrogen may not be your particular problem in this case.

Aphids are naturally controlled very well by releasing green lacewings in amongst your plants.

Make a visit to your lawn and garden store (a feed store if you are lucky enough to know of one) and buy a soil test kit. I bought one that tests pH,N,P and K. Since I like to fertilize (13-13-13) every time I look at the garden my soil was over the top on N P and K. pH was 6.5, just where it's supposed to be. The price of the kit was about $15. Peace of mind is worth it.

see..that's the thing..my tomatoes aren't dark green and the foliage isn't heavy. i even have a brandywine...and i know they're very N sensitive. it looks normal.

if anything...i'd be happy if the tomatoes were a bit greener...

Hello again, I'm not sure at all about California soil but if it's low on magnesium you'll get less green than you like. If it IS low then a tablespoon of epsom salts to a gallon of water per plant will perk things right up.