When you see the first truss of tomatoes, Scotkat. No need to rush to B&Q just yet :-).

My cherry toms,moneymaker and gardeners delight are all growing great all sown from seed by myself.

And already use my tomatoe food on other plants .

Hi Scotcat....."long time no see".....as Bulbaholic says....when the fruit starts to set.....then feed.......

FYI I didn't know until recently why you don't feed until the fruit starts to set. Apparently it's because if you feed too early the plant will make lots of leaves instead of fruit.