No need to feed if they are in the ground.

I normally through some bonemeal mix around Buxus balls in early spring and then about now. Perks them up after winter. I do sometimes use a Seaweed feed if I have some spare in a can both does spur on growth.

Don 't you find they go mad and grow too much if you feed them Botanic? Mine seem to grow quite fast enough without any encouragement!

Most of mine are a hedge by the driveway Steragram and somewhat exposed, so can get bronzed during winter. I also need them to thicken up. This year, yes, they have went made with growth.

The topiary ones in pots certainly get fed and watered regularly.

Are Buxom trees top feeders? ;o)

Lol!