Very Hot spot

Yep WO....convolvulous cneorum
A totally beautiful plant.....silver evergreen foliage, pure white spring and summer flowers and has a mounding and cascading habit.

Be prepared to cover with fleece if winter gets too cold

I would suggest mixing some horticultural grit with john innes....maybe 20%.

Why not pop in some blue anemone blanda bulbs in too around the edge? They will flower in April/May. Perfect time to buy and plant them

 

Ha ha, would I do that to you WO

No, although it is related it is as far removed from bindweed as you can get. It is a shrub without any vices. When you see it I'm sure you will love it WO

 

My usual advice for planting plants that like a hot spot.
Wait till next spring, give them time to establish over the summer before winter.

JI no 3 will just sit wet and soggy all next winter.

 

Burncoose is quite near to me WO but I usually go elsewhere...online is good. Garden centres and nurseries often start their reduced prices about now

Grit is important to the compost though for Cneorum. John innes on its own would be a bit too cloggy so a min of 20% grit, pref more, will do wonders. And a "mulch" of gravel sets the whole plant off and provides a warm dry collar for it

Pete has a point, perhaps, but planting now makes for a better established plant I think. However, prices will rise. You could get the plant asap and overwinter in gh if in doubt and pot up in spring.