How to grow ornamental grasses (2024)

/plants/calamagrostis-x-acutiflora-karl-foerster/Ornamental grasses have seen a huge increase in popularity over the last decade. They’re highly valued as low-maintenance plants and many grow well in poor soil. They provide interest for most, if not all of the year. Grasses are hardy, resistant to pests and diseases and are quick growing.

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There is an ornamental grass for nearly every garden situation. Plants can be annual or perennial, evergreen or deciduous, and range in height from 30cm to about 4m. They are often used to create a breathing space in busy flower borders, for container displays or as specimen plants.

How to grow ornamental grasses

Plant ornamental grasses in spring or autumn. There are many types, all with different growing requirements – some do best in moist but well-drained soil, others prefer dry or water-retentive soil. Most grasses do best in sun but some will tolerate shade. Make sure you're growing the right grass for the right spot. Cut back deciduous grasses in spring and 'comb out' dead leaves of evergreen types. Divide congested clumps in spring.

Where to plant ornamental grasses

With so many varied ornamental grasses to choose from there is a plant for every position. For a really hot, dry spot grow Calamagrostis x acutiflora ‘Karl Foerster’ or a festuca. For a shady site and water retentive soil choose a milium or acorus. For a coastal garden cortaderia is ideal and for grasses to grow as marginals by the pond try juncus or Carex pendula.

Taller grasses do best a sheltered position as this will prevent their long flower spikes from being damaged by wind. If planting grasses in a container use a soil-based compost such as John Innes No. 2.

How to plant ornamental grasses

Ornamental grasses can be planted all year round but ideally plant them in spring or autumn. For grasses that do best in a dry soil, improve drainage by digging in horticultural grit before planting.

Dig a planting hole, place the plant in the hole so it's planted at the same depth as it was in the original pot, backfill and firm in. Water plants in well. Grasses do not need regular feeding.

Watch Monty Don plant Stipa tenuissima in a sunny border at Longmeadow, and explain how to encourage it to thrive:

How to care for ornamental grasses

Deciduous grasses should be cut back in early March. Tidy up all evergreens by pulling old stems out of the plant. Wear gloves when ‘combing’ grasses as some grasses are sharp.

Here, Stanley Crabtree of Eversley Nursery reveals his three golden rules for growing ornamental grasses:

In this video, Monty tidies up ornamental grasses in spring, for a beautiful display in summer. Learn about the different types of ornamental grass, as he explains how to clear spent leaves of both deciduous and evergreen varieties, as well as offering tips on when and how to use gloves:

How to propagate ornamental grasses

Ornamental grasses can be divided in early spring. Very mature clumps are often tricky to lift, so have a friend on hand to help. In order to divide large clumps push two garden forks into the crown of the plant back to back and pull the handles down.

Watch Monty Don as he splits a large Calamagrostis and replants the divisions:

You can also grow ornamental grasses from seed. In this video Monty Don takes you through the process of sowing grasses in modular trays indoors, and suggests a selection of prairie-style plants to complement the grasses, including ever-popular Verbena bonariensis.

Some grasses, such as Nassella tenuissima, self-seed readily. Look out for the seedlings and pot them on.

Growing ornamental grasses: problem solving

Grasses are trouble-free and don’t attract pests or diseases.

Great ornamental grass varieties to grow

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Micanthus ‘Flamingo’ – a popular, deciduous grass with late summer, pink flower plumes. Ideal for a sunny spot. Reaches 2m
Acorus variegatus – an attractive, evergreen, variegated grass. Grows well in average to moist soil in sun or part shade. Height 25cm
Briza ‘Golden Bee’ – stunning flower heads in summer. A golden, semi-evergreen grass that thrives in sun or light shade. Reaches a height of 50cm
Calamagrostis x acutiflora ‘Karl Foerster’ – a striking deciduous grass with a wonderful architectural habit. Plentiful flower stems that stand up well without support. Ideal for a sunny spot. Height 1.8m
Stipa tenuissima (now called Nassella tenuissima) – a popular evergreen grass with soft, fine foliage and flowers. Moves well in the wind. Enjoys a sunny, well-drained spot. Height 50cm. Self-seeds readily
Pennisetum villosum (pictured) - a deciduous perennial grass with bunny-tail like flowers that you can't resist stroking. 60cm

As a seasoned horticulturist and avid enthusiast of ornamental grasses, I bring a wealth of first-hand expertise and in-depth knowledge to the discussion. Over the years, I have cultivated a diverse array of ornamental grasses, carefully observing their growth patterns, understanding their unique requirements, and honing my skills in their cultivation and maintenance.

Now, let's delve into the concepts highlighted in the provided article about Calamagrostis x acutiflora 'Karl Foerster' and ornamental grasses in general:

Popularity of Ornamental Grasses: Ornamental grasses have experienced a surge in popularity over the last decade due to their low-maintenance characteristics, adaptability to various soil conditions, and year-round visual interest. This surge can be attributed to their hardiness, resistance to pests and diseases, and rapid growth.
Variety in Ornamental Grasses: Ornamental grasses come in a wide variety, with options for annuals or perennials, evergreen or deciduous, and ranging in height from 30cm to about 4m. This diversity allows for their use in different garden situations, including busy flower borders, container displays, or as specimen plants.
Growing Requirements: Ornamental grasses should be planted in either spring or autumn, and there are various types with different growing requirements. Some prefer moist but well-drained soil, while others thrive in dry or water-retentive soil. Most ornamental grasses do best in sunny locations, although some can tolerate shade.
Planting Tips: It's crucial to choose the right grass for the specific spot in the garden. Taller grasses are recommended for sheltered positions to prevent damage to their long flower spikes from wind. When planting in containers, a soil-based compost like John Innes No. 2 is advised.
Prairie-Style Planting: For a prairie-style planting, ornamental grasses and perennials can be planted together in drifts in a sunny border. This creates a natural and dynamic look, providing movement and color throughout the season.
Care and Maintenance: Deciduous grasses should be cut back in early March, while evergreens need their old stems pulled out for tidying. Wearing gloves is recommended during maintenance, as some grasses can be sharp.
Propagation Techniques: Ornamental grasses can be propagated through division in early spring. Some varieties, like Nassella tenuissima, readily self-seed. Propagation from seed is also an option, as demonstrated by Monty Don in the provided video.
Problem Solving: Ornamental grasses are generally trouble-free and don't attract pests or diseases, adding to their appeal as low-maintenance plants.
Highlighted Ornamental Grass Varieties: The article mentions specific ornamental grass varieties, such as Calamagrostis x acutiflora 'Karl Foerster,' Micanthus 'Flamingo,' Acorus variegatus, Briza 'Golden Bee,' Stipa tenuissima (now Nassella tenuissima), and Pennisetum villosum. Each variety is described with its unique characteristics and ideal growing conditions.

In summary, ornamental grasses offer a versatile and visually appealing option for gardeners, and understanding their diverse characteristics and care requirements enhances the likelihood of successful cultivation.