Lots of water, its a bog plant, if you mean Primula rosea - I've got it in a pot so I can keep it wet enough, not having a really damp area to plant it in. Seems to tolerate sun quite well, as long as its damp enough.

Especially where you live semi shade - you are growing this plant out-with its normal habitat

I have it in a semi shady place though it is in alkaline soil with a beech leaf mulch.