I’ve been really looking forward to writing about this plant so please sit back and prepare to share my enthusiasm. My joy and delight at this time of year is a grass which rejoices in the wonderful name of Molinia caerulea subsp. arundinacea ‘Transparent’. Thankfully it is also known as the Purple Moor Grass which makes asking for it rather more straightforward.
In spring it starts into life, putting out hummocks of strap-like mid-green leaves which grow up and then arch over, rather like the Japanese Hakone grass, Hakonechloa macra, only taller. Then in July it swings smoothly into action, jetting long slim stems high above the leaves to well over a metre, each one of which carries airy pairs of purple, feathery spikelets right down its top third. These spikelets, which are the flowers, have a slight sheen to them which catches the light and as the stems move in even the slightest breeze, the result is a constantly moving veil of shimmer. But this is not the best feature – it becomes truly breathtaking after a shower of rain when each flower head carries its own drop of water which gleam like tiny gems as they move in the sun. ‘Transparent’ has the most enduring flower heads of all the ten varieties available in the UK.
In terms of maintenance it is one of the easiest grasses, requiring only that you cut down spent stems and foliage in late winter before the new growth begins. It flourishes easily on most soils provided they are not too dry, in full sun or partial shade. Pests appear to ignore it (though it may harbour the occasional snail).
I grow mine in the middle of a group of three David Austin ‘Cottage Rose’ bushes and the purple spikelets float very satisfactorily above the pale pink blossoms. Equally it would work beautifully in prairie planting settings in larger groups. It lasts well into winter, when the seed-heads turn black. I have to say that I have never had it set seed anywhere – and I cannot make up my mind whether this is an advantage of not, as a few extra plants would be rather pleasing. However, they may resent being disturbed so if you feel the need to propagate yours, then carefully dig up the clump in late spring when the growth is starting, break off chunks and pot them up and grow them on for a couple of years until they are big enough to establish in the border, and mark where they are planted to avoid accidental damage during dormancy
If you can make space for one, please give it a try – I’m convinced you will come to love it as much as I do.