I prefer to time my feedings by the fruit set, not the bloom buds. Since the buds have to open (bloom) before they can be pollinated and set fruit, you don't want to interfere with that process by feeding. When you feed a plant it triggers back to its green growth mode. So you want to wait until after the first flush of fruit has already set and is developing. Then you can feed to get a second (or third) new growth spurt and more blooms to set.

So I feed when planted (amend the planting hole well) and then again AFTER the first flush of fruit set.

Also stick with low nitrogen feeding. You want tomatoes, not giant green jungle plants with very few fruit. ;)

Dave

I think if you do a search on here you should find lots of info on fertilizing tomatoes. You want to fertilize throughout the growing season early you want a fertilizer higher in Nitrogen for leaf and stem growth, later a lower N and hiher P and K number for fruit development. The fertilers show these numbers on the boxes I think the one you said you were using is 15-15-15. I use that all year but go longer inbetween fertilizing when the plants are fruiting. Maybe everyweek to start and then every two weeks later.

Kimcoco,

I fertilize with bone meal, granulated tomato food and Epsom salts in the planting hole and sprinkle on some 9-15-15 side dressing at time of transplant. Then I wait until the first signs of blossom set when little fruit peep out and give the plants a good boost of one of those quick dissolving fertilizers with higher numbers on the middle and back end ... like Peters blossom booster formula.

Later in the season, I charge the plants up again with some granulated tomato formula or rose formula side dressing like from WalMart in those 3-dollar boxes. I also feed something like Miracle Grow and Epsom salts anytime the foliage looks like it's asking for some help with a green-up.

For container plants, I feed them more regularly like every two weeks with a quick dissolving product like Miracle Grow tomato or rose formula, plus Epsom salts.

So basically I feed initially for growth, next for blossom production, next for fruit development, then to sustain health and regrowth in the indeterminates. Works well for me.

I gotta say, I went back to using evil Miracle-Gro weekly all season this year, and my tomatoes look better than they have in years. To be fair, the weather has been amazing.

I have always amended the soil well, I compost, I add worm castings and other goodies, plus I do put a nice organic tomato fertilizer in the planting hole. But I've been having yield issues, so this year the changes made were: (a) after a small test run last year, I moved the bed to a sunnier spot. I did this by carting all of the dirt from the old raised bed to a new location, so the soil is the same. (b) I went back to pruning suckers and excess foliage in hopes of getting an earlier harvest of less, but larger fruit. (c) I went back to the blue kool-aid in addition to my usual stuff.

This year has been great. I freely admit that this is not data, but rather anecdata.