Here's a picture of my freshly-planted H. mac. 'Schloss Wackerbarth' a.k.a. 'Horwack' a.k.a. 'Pistachio'

It's supposed to have a low-spreading profile, and the potted specimen was already beginning to follow suit. Aside from the lateral growth at the base, the majority of it is tightly-clustered upright spires (hence being named after a castle, I suppose!). It does not grow thick stems but the stems are very rigid and sturdy. The leaves are also thick, small, and cupped, with a red tinge around the edges. There are a bunch of buds on this, but it's a bit too early to report anything on blooms. But I will continue to post back with its progression into the Summer.

For comparison, on the left in the picture is its other new neighbor 'Hortmahar' (opening cream-colored), with arborescens 'Annabelle' behind and 'Blue Cassel' to the right.

This Winter I'm simply going to throw some leaves on it and see how it does. Most everything on this north-facing hillside garden dies back quite a bit, so I'd be surprised if that isn't repeated here.