Planting ornamental grasses
Why, when and how
Contents
Ornamental grasses have become essential in our gardens. This comes as no surprise, as they possess valuable qualities cherished by gardeners: they offer soft, natural forms, are easy to grow once established, and adapt to various conditions. They captivate us with their elegant structure and help highlight other plants, creating a stunning backdrop for flower beds or a uniform carpet that makes vibrant blooms stand out. With their flexible foliage, they bring a very natural, both wild and contemporary effect to the garden. Depending on the variety, they can be deciduous or evergreen. Some boast beautifully coloured and variegated foliage. In late summer and autumn, they produce delicate, airy flowering spikes. Discover all our tips for successfully planting and growing them in your garden!
When to plant ornamental grasses?
Ornamental grasses can be planted in spring, from March to May, or in autumn, during September and October. In regions with cold, wet winters, it’s best to plant them in spring, as young plants will have all summer to establish themselves before the first frosts. However, in milder climates, autumn planting is ideal: the still-warm soil and regular rainfall encourage root development. Just be careful not to plant too late in autumn, especially if your soil is heavy and poorly drained, to protect your grasses from excess moisture and early frosts.
Where to plant them?
Most ornamental grasses thrive in sunny spots or light shade, but few tolerate dense shade. They will do well in any well-drained soil, even if not particularly fertile… They offer an excellent solution for greening poor, dry soils. Or for creating a low-maintenance garden that requires no watering, fertilising or upkeep! However, some grasses (for example, Hakonechloa) prefer moist soils, while rushes, Giant Reed (Arundo donax) or Common Reeds (Phragmites australis) will thrive at pond edges!
Moreover, some grasses adapt very well to container cultivation! Consider for example Pennisetum setaceum, Carex oshimensis or Hakonechloa macra. When combined with other perennials like verbenas or anthemis, they’ll add structure and airiness to your planters!
→ Read also: Which grasses for sandy soils?, Which grasses for chalky soils? and Which grasses for acidic soils.
Ornamental grasses add lightness to planters! Here, Pennisetum with Anthemis, Sanvitalia, Bacopa and Bidens. (Copyright Friedrich Strauss – Biosphotos)
How to plant ornamental grasses?
For a successful visual effect, plant your ornamental grasses in groups. Smaller varieties, such as fescues, sedges or stipas, benefit from being grouped in at least five plants to create harmonious carpets or backdrop for flower beds. Planted en masse, they add structure and lightness to your landscape compositions.
To successfully plant your ornamental grasses, follow these simple steps:
- Dig a planting hole twice as wide as the root ball. If your soil is heavy or poorly drained, add gravel or coarse sand to the bottom to ensure good drainage.
- Place the root ball in the hole, making sure the plant is positioned at the same height as in its original pot. Do not bury the base of the stems, as this could harm the plant.
- Fill the hole with the excavated soil and lightly firm it down
- Water thoroughly to help the plant establish.
- Once well established, ornamental grasses require little watering, but it is important to keep them hydrated regularly during the summer following planting to encourage root development.
Good to know: Some grasses, such as reed canary grass (Phalaris arundinacea), have invasive rhizomes. Avoid planting them near delicate small plants that could be smothered.
How to care for ornamental grasses?
Once well established, ornamental grasses require little maintenance, especially if their location suits them. At the end of winter, cleaning up the clumps is the main task to consider: deciduous varieties should be cut back to ground level to stimulate their regrowth in spring, while evergreen varieties simply need a “combing”. This involves removing dead leaves by hand or with a rake to restore their neat appearance.
Some vigorous grasses, like Arundo donax or Carex muskingumensis, may require occasional control to prevent them from taking up too much space. If their growth becomes excessive, don’t hesitate to reduce their size or remove unwanted parts.
Finally, we recommend dividing your grasses every 3 to 5 years. This task, to be carried out in spring or early autumn, helps rejuvenate the clumps, improve their growth and multiply your plants for other areas of the garden. This way, your grasses will remain beautiful and vigorous year after year!
To learn more, check out our video guides Pruning ornamental grasses and Dividing ornamental grasses. And our articles: Ornamental grasses: those to prune, those to comb.
Also discover Olivier’s video on Hakonechloa macra.
- Subscribe!
- Contents