Ornamental Grasses & Late-Season Bloomers

Tune up your garden with some late-season pizzazz! Ornamental grasses can provide color, texture, structure, and movement in your landscape with minimal maintenance. Discover the best ornamental grasses to grow, their basic care and maintenance needs, and which perennials and shrubs compliment them.

In addition to their graceful grass foliage, many varieties have showy “flowers” and seed heads that provide late summer and fall interest as well as seeds for local birds. Each genus of ornamental grass has a slightly different style of inflorescence—many varieties can be easily identified by their different “blooms”. Most grasses are deer-resistant and susceptible to very few pests or diseases, and many are drought-tolerant once established; see specific lists below for best selection. Ornamental grasses can be fertilized with lawn or turf fertilizer (NO Weed & Feed) or an all-purpose blend.

Things to Consider

• Design with mature height and width in mind to avoid overplanting (wide clump by third year)
• Plant winter dormant grasses in areas with easy access for maintenance and pruning
• Grasses and spring-flowering bulbs are great partners as they alternate seasons. Many grasses are small or dormant in early spring and later season’s growth hides bulb foliage as it fades.
• The soft texture of grass foliage provides nice contrast with boulders and hardscaping
• Durable and flexible, grasses may be excellent choices for high-traffic or play areas
  

Ornamental Grass Care & Maintenance

Some grasses remain evergreen in winter while others go dormant. Many of the tallest-growing varieties go dormant for winter with the exception of pampas grass (Cortaderia). Often, evergreen grasses have a low, mounding or clumping growth habit. As a general rule, grasses with a golden or chartreuse color do better with late-afternoon sun protection and those with blue-grey or silver coloration may do best in full sun.

Winter dormant grasses turn a straw color in winter, but remain intact and above ground, providing winter interest and movement in the garden. They need to be pruned annually, but can be cut back in late fall or left up through winter and pruned in early spring before new growth begins. Some grasses take on pretty fall colors before going dormant for winter such as Switchgrass and Japanese Forest Grass, and many birds feed on the dried seed heads.

Evergreen grasses occasionally need to be combed or roughly raked to pull out dead foliage—evergreen grasses seldom need to be cut back to the ground and many often do not respond well to this practice.

Most ornamental grasses have a clumping growth habit and increase in diameter each year; after 3–5 years, the clump often begins to appear dead or thin in the center—a great indication that it is time to divide. This can be done in late fall or early spring before new growth begins.

Evergreen Grasses

• Acorus
• Anemanthele lessoniana (Pheasant Grass)
• Carex buchanaii
• Carex comans
• Carex flageliffera
• Carex morowii ‘Ice Dance’
• Carex oshimensis ‘Evergold’
• Carex phyllocephala ‘Sparkler’
• Carex testecea
• Cortaderia
• Festuca
• Helictotrichon
• Juncus ‘Spiralis’
• Juncus ‘Unicorn’
• Juncus effuses
• Liriope
• Ophiopogon ‘Nigrescens’ (Black Mondo Grass)

Running Grasses

*can become invasive; suggested for container growing to control spread; we choose not to carry many of these

• Arundo donax
• Elymus glaucus
• Hakonechloa
• Imperata
• Luzula sylvatica
• Phalaris (Ribbon Grass/Canary Reed Grass)
• Equisetum (Horsetail Rush)

Grasses for Containers

*most evergreen grasses make great container plants!

• Carex elata ‘Bowles Golden’ (semi-evergreen)
• Carex ‘Ribbon Falls’ and ‘Feather Falls’
• Equisetum sp.
• Hakonechloa
• Imperata
• Miscanthus ‘Morning Light’
• Stipa tenuissma
• Uncinia rubra (Red Hook Sedge)

Annual Grasses for Containers:

• Pennisetum glaucum ‘Purple Majesty’
• Pennisetum setaceum ‘Rubrum’
• Scirpus filiformus
• Cyperus papyrus

Grasses for Raingardens & Bioswales

• Acorus sp.
• Carex nigra
• Carex obnupta (PNW Native)
• Deschampsia cespitosa
• Juncus sp.
• Miscanthus sinensis

How to Extend Perennial Bloom Time or Promote Re-Bloom

Well-watered and properly fertilized plants tend to perform better than those that receive little care. On average, mid to late August should be your last feeding for the perennial garden for the year. Applications of kelp meal may be done later and may increase winter hardiness of plants.

Many spring-blooming perennials will repeat bloom in late summer or fall if they are deadheaded promptly after the spring flowers fade. Delphinium and Foxglove are good examples of this; when the spring flower stalk is removed after flowering, the plant can reinvest its energy in itself, producing a more lush plant that will usually form a flower spike for later in the season. The second flowering is often slightly smaller or less showy than the first one.

Chrysanthemums (Mums)

*also applies to late-blooming Asters, Sedum ‘Autumn Joy’ (upright types), and tall-growing or dinner-plate style Dahlias

Chrysanthemums seem to be the official signal of fall. Although sold as seasonal color, most are winter hardy enough to return in the spring if grown in well-draining soil. For mums that return the following spring, they need some special care to ensure that they grow bushy and compact and wait to flower until late summer or fall.

To best care for perennial mums:

• When the plant has reached 6 inches tall, pinch back the top third of growth (top 2 inches).
• Continue cutting back by one-third every 3 to 4 weeks until around the 4th of July when you should leave the plant alone to form flower buds and bloom.
• This practice helps to form a dense, slightly shorter, more compact plant with multiple buds that bloom in late summer or early fall.