Feeding snowdrops and in fact all forms of plants can be very beneficial as long as the correct nutrients are given and at the right time of year.
The three basic nutrients found in plant foods are nitrogen (N) required for growth, phosphate (P) required for strong root growth and potash (K) required for flowering and fruiting.
I like to feed my snowdrops twice a year.
In the autumn as each basket is lifted and re-planted I will mix a handful of blood, fish and bone meal (N-P-K of 5-5-6) into the compost. For any baskets that are not lifted or for snowdrops that are planted in the open garden I scatter a few handfuls onto the surface of the soil and gently work it in.
I prefer to use blood, fish and bone meal as opposed to just bone meal, because the latter does not contain potash (K) which I find essential in helping to keep the bulbs healthy.
In the spring (usually in April) I will give the snowdrops a liquid feed of phostrogen
(N-P-K of 14-10-27) just as a boost.
For plants that are grown in the greenhouse I prefer to use tomato food (N-P-K of
6-5-9) purely because it is a liquid and is much easier to make up small amounts.