Hydrangea aspera ‘Hot Chocolate’
Although living in Ireland has reinforced my respect and created a whole new affection for macrophylla hydrangeas I have always been fond of lots of the other species. This is because many of these are more tolerant of drought and limey soils and many have features other than just their flowers to make them gardenworthy.
One that I have often planted is Hydrangea aspera. This rather coarse plant from the Himalaya and China is an upright shrub to 3m high and across with pairs of rough leaves and bark that shreds as the plant ages. In late summer the shoot tips are dressed with clusters of flowers in typical lacecap formation with a few sterile florets around the edge and a centre of fluffy fertile flowers in shades of pink and mauve. In its typical form it is a lovely shrub for a large border but perhaps not in the top class of shrubs to make it really to be recommended for a small garden.
That has changed a little with the introduction of ‘Hot Chocolate’ (introduced in 2012) which is like the species but has lovely purple-flushed foliage, more intense on the reverse, and flowers that are more intensely coloured. The young foliage has the best colour and it tends to turn green by summer though new growth will still be colourful. The first flowers open in late July here and although they are now past their best (the photo above was taken in late August and the sterile florets had already started to turn over rather than face upwards) they still have some beauty. It is a shrub for average soil in sun or part shade and although it is not recommended for thin, chalky soils it should be OK in limey soils where macrophylla types would fail. It can be lightly pruned or tidied up in spring and should be completely hardy in the UK and Ireland.
Geoff’s rating
8/10
Garden rating
7/10
The Biking Gardener 
There are several healthy and lovely H. aspera in Rowallane. One of the owners, Hugh Armytage Moore, collected them in the Edwardian era. The hydrangeas in the walled garden are from cuttings of his original plants. I love their furry leaves and frothy flowers.
It is nice that plants can link us to the past in this way. And yes, they are dual purpose plants with attractive leaves. It is so easy to get obsessed with flowers and forget about the rest of the plant but these win on all counts 🙂
I put my first ‘hot chocolate’ in the ground but it died! My new o e I have managed to over winter in a large tub and is now coming into flower but I would like to know how to prune it? I live in the northwest and my garden is fairly sheltered but can have a high water table in the winter and that is why I think my first one died. I just love it when the sun shines through its leaves.
I think the high water table could have been the problem too – this is a very different plant to the more common ‘mop head’ types which need plenty of water. This doesn’t really need a lot of pruning but you can trim it in spring of necessary. I agree that the leaves are lovely in the sun 🙂