what should i do with my apple tree

I was just looking at the tomatoo feed in the store and it says to only use it when i see little signs of small fruit on the plant. Is this a normal instruction. The plant only has flowers so according to the tomatoo food i shouldnt be using it just yet

 

The compost will have enough nutrients in it to see the plants through until the feeding time comes round.

 

So you mean until there are signs of small fruit ?