Grasses and Bamboos
What is an ornamental grass?
An ornamental grass is a grass which is allowed to grow to its full potential and show off its ornamental qualities. They are most often perennial, needing to be cut back in the Spring and then re-grow to flower in the Autumn. However, some are evergreen and some are annual. There is a wide variety of grasses available suitable for many types of site condition.
Bamboos belong to the grass family. They have an evergreen and woody structure and have shallow, greedy roots. They don’t do well on shallow chalky soils, waterlogged soils or soils that dry out too much.
Using grasses and bamboos in the garden
Grasses can add height, texture, movement and sound to the garden and work well in mixed borders.
They add interest in late summer and autumn when many other flowering plants are fading.
Bamboos are fantastic plants with tall elegant stems and interesting foliage and can be used as specimen plants, as wind-breaks and for screening unwanted views. They give structure and all-year interest, and provide sound and movement in the breeze.
However, as they have an exotic oriental look and feel, they will not work particularly well in a traditional country style garden.
Beware of the invasive bamboo varieties! Some varieties are clump forming and keep to a relatively small area, others are invasive and are difficult to eradicate once established. If you do want to use an invasive variety, you need to add a barrier 60cm deep around the rootball and set slightly above the ground level to restrict its spread. You can use four paving slabs sunken into the ground to achieve this, or specific root retaining membrane.
Pruning grasses and bamboos
Grasses and bamboos should never to cut half way down a stem or sheared over like an evergreen shrub,
For grasses, if it is an evergreen variety, just comb through with your hands to remove the old foliage. (It's best to use gloves to avoid cuts.) For deciduous grasses cut right down as close to the ground as you can get, before the new growth starts which will be around the middle of February.
For bamboos, older stems could be cut out from the base if the clump if it is getting congested.
The exception is if you are moving a mature bamboo. I have successfully moved a 10 year old bamboo by cutting it down to the about 20cm from the ground in the spring. Within a few weeks new shoots had been produced.
Examples of grasses and bamboos
Click on any of the images below to enlarge and read more
Calamagrostis x acutiflora 'Karl Foerster' is a tall, very upright grass that adds height and structure to a garden.
Carex testacea is an olive-green ornamental grass which turns a warm copper colour in the autumn.
Deschampia cespitosa ‘Bronzeschleier’ has silvery flower plume in late summer.
Hakonechloa macra ‘Aureola’ is a relatively low growing mound-forming grass with yellow striped leaves. It has an oriental feel about it and works well with Hostas and Acers and at the front of mixed borders.
Miscanthus sinensis ‘Morning Light’ is an elegant silvery-green upright grass which gently arches as it matures.
Ophiopogon planiscapus ‘Nigrescens’ is a small black evergreen grass that works well at the front of a border, in containers and among small white-flowered plants like Snowdrops.
Panicum virgatum ‘Rehbraun’ is a deciduous grass with upright foliage which turns reddish-purple in autumn.
Phyllostachys aureosulcata f.aureosulcata is an elegant bamboo with lovely golden stems.
Stipa arundinacea (Anemanthele lessoniana) is a good evergreen grass that tolerates heavier soil and some shade, and it turns a lovely golden/green colour with soft flowers in the autumn.
Stipa gigantea offers height and looks great among perennial planting
Stipa tenuissima is a short, soft grass which moves gently in the breeze and looks good among delicate perennials such as Aquilegia.