The Plant Heritage area of the 2019 Hampton Court Palace flower show featured a superb display of the national collection of Hakonechloa. These are clump forming perennial grasses from wooded and mountainous areas of Japan. As such they are totally hardy but there are a few things which need to be understood about growing them successfully in gardens here.
H. macra and its variegated cultivars are among the most attractive of ornamental grasses. They make a startling edge to a border or in a rock garden. Solitary clumps in pots or containers make exceptional feature plants on the patio or in the greenhouse. However the most colourful variegated forms perform best in partial shade and can scorch or bleach out their leaf colours in full sun.
A well-drained soil is also essential since, if these plants get waterlogged, they become prone to dieback and rotting off, especially over winter. This is particularly true of the golden leafed variety H. macra ‘Sunflare’ which we have found to be temperamental especially if grown in full sun in a hot polytunnel.
H. macra varieties spread slowly to form mounds of smooth arching leaves up to 10in long. From late summer to mid-autumn the clumps produce needle-like pale green three to five flowered spikelets in open panicles which can be around 6in in length. H. macra ‘Aureola’ has bright yellow leaves with narrow green stripes while H. macra ‘All Gold’ is as its name implies. In late summer and autumn more and more of the leaves become flushed red as you can see in some of the accompanying photographs here.
Hakonechloa are best lifted and gently divided by hand with a sharp knife to produce new plants. These are best grown on in the greenhouse for the first year before planting out in the garden.