Ornamental grasses bring out the best in your border, contrasting and complementing the flowers.
But they were considered ‘fashionable’. Consequently many of us overlooked them.
Until now, they haven’t been part of a traditional herbaceous border.
But now we increasingly appreciate that ornamental grasses add light, texture and movement to a border.
They have gone beyond ‘fashion’ and are now perennial border staples. And they are very easy to look after.
I visited Paul Seaborne of Pelham Plants, who is passionate about grasses, to find out how to choose and use them.
Pelham Plants is in Sussex, and his adjoining garden has open days for the NGS. And Paul also sells his plants via the Plant Fairs Roadshow.
Here are seven brilliant ornamental grasses and how to make the most of them in your garden.
Top ornamental grasses for your garden
- Golden Oat Grass/Stipa gigantea -a stunning statement grass that needs minimal care
- Feather Reed Grass/Calamagrostis ‘Karl Foerster’ – the garden designers’ favourite grass for structure
- Chinese Silver Grass/Miscanthus Yakushima Dwarf – as a single statement or create a grass ‘hedge’
- Transparent Moor Grass/ Molinia ‘Transparent’ -adds ‘barely there’ movement and magic to a border
- Fountain Grass/Pennisetum ‘Black Beauty’ – there’s a huge range of chunky pennisetum grasses with beautiful bottle-brush flowers
- Pheasant’s Tail Grass/Anemanthele lessoniana – a resilient autumn favourite for dry gardens or partial shade
- Japanese Forest Grass/Hakonechloa Macra – add light and structure to shade. Good in pots.
Golden Oat Grass/Stipa Gigantea
Hardy to: Minus 23C/minus 10F
Paul grows Golden Oat Grass (Stipa gigantea) ‘Gold Fontaene’ in his cottage garden. ‘Just because it’s a tall grass, that doesn’t mean it has to be at the back of a border,’ he says.
Place it at the front or at a corner. It’s tall, feathery stems are almost see-through. He particularly likes to place it where it can be backlit by the rising or setting sun.
Although it looks fragile, he says that the slender stems are quite strong and resilient. The seed-heads empty soon after flowering, but remain on the plant so you get the full effect of an ornamental grass throughout winter. A few stems may collapse, but otherwise, cut it to the ground in spring.
Paul uses a hedge-trimmer, so the job takes only a few minutes. And that is the only care the golden oat grass needs all year!
Golden Oat Grass (Stipa gigantea) ‘Golde Fontaene’ in Paul Seaborne’s garden. It’s almost transparent – you can see other plants or the house through it.
Feather Reed Grass/Calamagrostis ‘Karl Foerster’
Hardy to: Minus 40C/minus 40F. 1.5m-1.8m high
Calamagrostis ‘Karl Foerster’ is loved by garden designers everywhere. It is very straight and upright, forming columns of golden grass from summer through to winter.
I have seen it used as a ‘hedge’, where it gives the impression of a row of soldiers on parade.
Paul used to have evergreen shrub columns in one of his borders. But he felt they dominated the borders, so he took them out and used Calamagrostis ‘Karl Foerster’ as a punctuation point instead.
This is also a tall grass, but it is quite narrow so it is suitable for the middle or back of a border.
Feather Reed Grass (Calamagrostis) ‘Karl Foerster’ has a very upright, sculptural habit, with straight golden stems. It makes it good for ‘punctuation points.’ The top photo shows a garden designed by Michael McCoy – read his tips in Naturalistic Planting Design – how to get it right.
Chinese Silver Grass/Miscanthus sinensis ‘Yakushima Dwarf’
Hardy to: There are many varieties of miscanthus and hardiness varies. ‘Yakushima Dwarf’ is hardy to Minus 28C/minus 20F
There are many sizes and varieties of Miscanthus or Chinese Silver Grass. Heights vary from 60cm/2ft to 1.8m/6ft.
Paul’s ‘Yakushima Dwarf’ is about waist-high and he uses it as a hedge.
Ornamental grasses make good hedges because they filter wind, but don’t take too much moisture or nutrient from the soil.
The only disadvantage is that Miscanthus are not year-round. You should cut them down to the ground once a year in spring. However, they grow up quickly and provide movement and structure in late summer and over the winter.
Miscanthus also make good punctuation points – on a corner, in the middle, front or back of a border, depending on the height.
Chinese Silver Grass (Miscanthus sinensis) ‘Yakushima Dwarf glows in Paul’s border, adding light and movement. It also acts as a ‘hedge’, filtering the wind and protecting the perennials on the other side of the border.
Transparent Moor Grass/Molinia ‘Transparent’
Hardy to: Minus 28C/minus 20F. Hieght 1.5m-2.5m
This is a very transparent grass. It is very tall and airy, but Paul recommends putting it at the front of a border or on a corner, because it doesn’t block anything.
You can see all your flowers through it, so it adds texture and movement to a garden.
This grass looks good from summer until the first frost. After that, its stems collapse. ‘And you clear it all away,’ says Paul.
The following spring Molinia ‘Transparent’ will grow up again. So it is virtually maintenance-free, apart from clearing away the dead stems once a year!
Molinia ‘Transparent’ adds movement and texture to a corner of Paul’s garden. You can see all the colour through it. Another of the easy-care ornamental grasses, although they are all comparatively low maintenance.
Fountain Grass/Pennisetum ‘Black Beauty’
Hardy to: there are many varieties of pennisetum so hardiness varies. ‘Black Beauty’ down to minus 28C/minus20F. Height 80cm-1.5m
There are many varieties of pennisetum, but ‘Black Beauty’ is one of Paul’s favourites. ‘It’s a lump of grass, so it needs to be on the front edge or to dominate its position. Put soft planting around it.’
This needs ‘good light and a good depth of soil. It can be quite a thirsty plant.’ Many ornamental grasses are good for ‘dry gardens’ or gravel gardens, but not this one.
Cut down to the ground once a year in spring.
Pennisetum ‘Black Beauty’ is quite a chunky grass with distinctive black-tinted plumes. Ideal for the front of a border or as a statement plant.
Pheasant’s Tail Grass/Anemanthele lessoniana
Hardy to minus 6C/21F. Height 90cm/3ft
Another garden designer favourite. Unlike many grasses, this is good in partial shade, although it also likes full sun. Has lovely autumn colour.
This is considered partially evergreen, so don’t cut it down to the ground. Comb out the dead leaves with gloved hands.
Good at the front of a raised border, as it arches gracefully to the ground.
Pheasants Tail Grass (Anemanthele lessoniana) in my own border, adding light to a grouping of purple asters.
Japanese Forest Grass/Hakonechloa Macra
Hardy to minus 28C/minus 20F. Height 30cm-50cm
This low-growing grass is popular for light shade, but don’t over-crowd the border when it’s getting established. It’s also reasonably drought-resistant but will need watering in its first year.
Paul grows it beneath a cornus and beside a hedge, alongside hardy geraniums, so it is a useful ground cover plant.
It’s also good in pots and containers, as are most grasses. (The very tall ones are more vulnerable to the wind in pots.)
Two shades of Japanese Forest Grass (Hakonechloa macra) in the nursery at Pelham Plants, both in pots.
See more of Paul’s garden in video
Paul and his partner created their garden while developing the Pelham Plants nursery, so most of the plants in the garden can be bought from the nursery. Growing the plants in a garden also gives Paul a good insight into what the plants need and how to make the best of them. See the garden in video here.
See some good plants for planting in spring picked by Paul and other independent nursery growers from the Plant Fairs Roadshow. And see their pick of good plants to plant in autumn here.
Paul’s tips on creating a micro-climate in your garden are particularly useful.
Should ornamental grasses be cut back every year?
Firstly, find out if your ornamental grass is evergreen or deciduous.
Deciduous ornamental grasses usually change colour in the autumn, then many will give you sculptural dried seedheads and stems throughout winter. These grasses need cutting to the ground every spring.
Check the care instructions for your variety. If you cut the more tender grasses too early, a frost may get to the plant. But otherwise it’s simple!
If your ornamental grass is evergreen, then the leaves will stay green or mainly green throughout the year. Some of the leaves will change colour and die off, so you will get a stippled effect.
Most of the evergreen grasses should NOT be cut down completely to the ground. Rake the dead leaves out or ‘comb’ through the grasses with a gloved hand.
You can do this in spring or at any time when the grass seems to have too much dead in it.
Pin to remember the best ornamental grasses
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