Rake in some Growmore around the base.

You have not been listening to the right television programs or you would know that Crinodendron does not grow in Scotland, never mind on Orkney :-).
I know of Crinodendron growing in a number of gardens across Scotland, including our own until it got badly frozen this winter. I guess that you garden must be quite sheltered.
Provided that the Crinodendron is growing in good, humusy garden soil it should not really need feeding. If you want to feed it just use some bonemeal around the roots.