Plant Spotlight – Stipa gigantea

Plant Spotlight: Stipa gigantea

Golden oats (Stipa gigantea) is well named. A large evergreen grass up to 2 metres tall, in summer it produces long panicles of arching oat-like flowers that emerge purple before turning golden-brown as the season progresses and the deciduous leaves of other species begin to change colour and fall.

They are extremely easy to grow. All that is required to produce a show-stopping specimen is plenty of room in a sunny spot. They prefer a moderately fertile, free draining soil, but in truth will grow almost anywhere as long as light levels are good and temperatures don’t fall below minus 10 degrees C.

We grow them here mixed with other grasses and summer flowering perennials in the new borders on the Arboretum Lawn, and in and around the herbaceous borders by the National Collection of Anthemis.

They are particularly good planted with late-season perennials that flower on the cusp of autumn when their golden ‘oats’ are just beginning to mature. Sedums combine well, as do asters, coneflowers and Echinacea. Annuals – like Zinnias – that need lots of heat and can take a long time to get going in the summer make great bedfellows too.

Superficially delicate, they are in fact rather robust, often growing extremely large as their botanical name suggests. They can certainly hold their own – and even look good – with other substantial border bullies like giant fennel and ornamental cardoons.

Herbaceous perennials that hold their form and dry well as they die-back in autumn also make classic companions, persisting into winter, catching frost and snow, and providing habitat for over-wintering insects. Plants with interesting dried seed heads like sea hollies, honesty or bergamot are particularly good examples.

Planted en-masse in large borders alongside these floriferous perennials, golden oats can help create a prairie-style feel to the garden. But they have such a graceful, architectural form, that they also make brilliant statement plants when planted alone or in small numbers – particularly if planted either side of a path or entranceway where they can stand guard like sentinel garden wards.

Little ongoing care is required in order to keep your golden oat plants looking good. The dried flower heads should be cut and removed in spring to allow room for the new seasons flowers to emerge. The spent flower heads are often still in good condition and intact even at this time of year, and can be brought inside once cut and used in dried displays rather than wasted on the compost heap.

Otherwise, simply ‘comb’ through your plant annually to remove any dead or dying foliage, and divide overly large, congested plants in late-spring or early summer, in order to rejuvenate old and exhausted clumps.