Read this green guide on how to properly care for switchgrass. The most beautiful panicum varieties for beds and containers with tips on growth height and autumn color.
How do you care for switchgrass?
Switchgrass (Panicum virgatum) is a hardy ornamental grass that is planted in sunny to shady locations. It is characterized by its upright, clump-forming growth habit and spectacular autumn color. Regular water supply and annual pruning in late winter promote he althy growth.
Profile
- Scientific name: Panicum virgatum
- Family: Sweet grasses (Poaceae)
- Growth type: Perennial
- Growth habit: upright, clump-forming
- Growth height: 50 cm to 250 cm
- Leaves: stalks
- Leaf color: fresh green, blue-green, red-brown
- Flowers: terminal panicles
- Flowering period: July to September
- Roots: Rhizomes
- Winter hardiness: hardy
- Use: ornamental grass, privacy screen
Flowers
From July onwards, richly branched, delicate flower panicles rise from the clump of switchgrass. Characteristic of the inflorescences on sweet grasses are numerous spikelets that gather together to form long panicles. The airy veils of flowers decorate the garden until September. In autumn, mature spikelets release their seeds for propagation by self-sowing. It is important to note for small gardens that the seeds of most varieties are numb and do not germinate.
leaves
The magnificent garden effect of switchgrass is primarily based on the spectacular autumn color of its leaves. Tightly upright stalks appear in dense clumps of leaves and overhang in arches over the course of the summer. When the fluffy flower spikes rise above the stalks, a fireworks display of colors begins. The following table provides an overview:
| Summer coloring | Autumn Coloring |
|---|---|
| freshgreen | yellow brown |
| teal | golden yellow to dark yellow |
| dark green | brown-red to red |
| teal/red tips | red-violet |
| silvergreen | yellow |
Roots
Switchgrass spreads with underground rhizomes. In contrast to other sweet grasses, such as bamboo (Bambusoideae) or pampas grass (Cortaderia), switchgrass does not tend to spread invasively in the garden.
Excursus
Perennial of the Year 2020
The Association of German Perennial Gardeners named switchgrass the perennial of the year in 2020. With this title, the garden experts bow to the high ornamental value with sensational autumn colors and the frugal requirements of Panicum. This means that the ornamental grass is now on a par with other title holders, such as Geranium (2004), Phlox (2006) and Bergenia (2017). Get to know the unique properties of switchgrass in more detail in the following video:
Planting switchgrass
In the bed, switchgrass is suitable for representative individual placement or group planting with a privacy function. Combined with the right plant neighbors, the colorful stalks come into their own particularly well. Compact varieties decorate the balcony in pots. Read about where and how to optimally plant switchgrass in the following sections.
Location
At this location the switchgrass unfolds in all its glory:
- Sunny to sunny location (at least 6 hours of sunshine daily)
- Normal garden soil, preferably moderately dry to freshly moist, well-drained, nutrient-rich
Optional locations: open space, perennial bed, flower border, rock garden, gravel bed, front garden, balcony, terrace, roof garden.
Plants
The best time to plant is in spring. When the soil warms up, the switchgrass can immediately start growing its roots. Before planting, soak the potted root ball in water. Place the water-soaked, now potted plant deep into the ground so that its buds are flush with the surface of the soil. If the location is close to the garden pond, line the planting hole with a root barrier to protect the pond liner from the rhizomes.
For planting in a pot, we recommend a structurally stable substrate without peat. Mix a few handfuls of expanded clay, sand or lava granules into the potting soil to improve permeability. Use a planter with holes in the bottom for drainage. Ideally, cover the bottom of the vessel with a 5 to 10 cm high layer of expanded clay balls or grit as drainage.
Combine switchgrass
With its late shoots, switchgrass acts as the perfect backdrop for early bloomers. The summer green stalks with a blue shimmer harmonize impressively with colorful perennials. A symphony of colors shines in the autumn garden when you combine switchgrass with autumn bloomers. Get inspired by these ideas:
- Early bloomers: Daffodils, tulips, bluetongue leeks (Allium karataviense)
- Summer bloomers: Speedwell (Veronica teucrium), Flame flower (Phlox), Coneflower (Rudbeckia)
- Autumn bloomers: Autumn aster (Aster dumosus), Autumn monkshood (Aconitum carmichaelii), Winter aster (Chrysanthemum hortorum)
Care for switchgrass
The switchgrass is very easy to care for. You do not need to fertilize the ornamental grass. Important care measures include regular watering and pruning at the right time. Regardless of robust winter hardiness, simple protective measures for the cold season make sense. It is worth taking a look at the following care instructions:
Pouring
A consistent water supply is the guarantee for the picturesque autumn colors. Water a switchgrass when the soil in the bed or container feels dry. In the planter on the sunny south-facing balcony, watering is required more frequently than when planted out in fresh, moist garden soil. Because waterlogging reliably kills the magnificent ornamental grass, check the moisture content in the substrate using a finger test before each watering.
Wintering
As a perennial, switchgrass is well hardy. Biting cold cannot harm the ornamental grass. Winter problems are caused by constant wetness and snow pressure. In the pot, the root ball of a switchgrass is vulnerable to frost. This is how you overwinter Panicum properly:
- Tie the stalks together in late autumn with sisal cord.
- In the bed, pile up the root disk with leaves and pine fronds or needle twigs
- Place planters on wood and cover with garden fleece or bubble wrap
If winter comes with bright sunshine and frosty temperatures, the switchgrass can dry out. In fact, winter drought stress is the most common cause when ornamental grasses no longer sprout in spring. Therefore, water the clump of leaves even in winter on mild days when neither rain nor snow falls.
Cut back
In late winter, pruning the leaf horst makes room for the fresh shoots. Cut back the switchgrass in February or March before the first green leaf tips appear. How to do it right:
- Put on gloves to protect against sharp edges of leaves
- Suitable cutting tool: long knife, secateurs, perennial sickle
- Grip the stalks in bunches with one hand
- Cut tufts of leaves hand-width above the ground
Were you surprised by this year's budding? Then put the cutting tool aside. A cut into the green tips of the stalk leaves brown discoloration that disfigures your switchgrass. In this case, comb out the dried stalks with both hands.
Propagation
Switchgrass is easy to propagate by division. In contrast to the time-consuming sowing of seeds, the variety-specific properties are retained with vegetative propagation. The best time is in the spring after pruning. This is how it works:
- Dig up Horst with a spade
- Place the root ball on a solid surface
- Cut into fist-sized pieces with a knife or spade
- In a sunny location, plant each bale segment as deep as before
- Watere regularly on the day of propagation and afterwards
You don't have to completely dig up large switchgrass varieties. Using a freshly sharpened spade, pierce the outer parts of the clump of leaves and replant the sections elsewhere. On this occasion, the mother plant is rejuvenated, which is reflected in the intense coloring of the stalks.
Popular varieties
The following variety selection introduces you to the most beautiful switchgrass for beds and containers:
- Northwind: Columnar switchgrass with a height of 180 cm, decorative, blue-green stalks, bright yellow autumn color.
- Cloud Nine: largest switchgrass, majestic growth height up to 250 cm, delicate, brown panicles, blue-frosted stalks.
- Switchgrass Heavy Metal: magnificent ornamental grass, shimmering metallic blue-green stalks with blue-green panicles, up to 150 cm high.
- Holy Grove: impresses with bluish leaves, red-brown flower spikes and red stalk tips in late summer, growth height up to 100 cm.
- Prairie Sky: gorgeous, delicate pink panicle veil from July, blue-green foliage up to 150 cm high.
- Panicum virgatum 'Shenandoah': enchanting 80 cm small variety with blue-green summer stalks and fluffy, pink-brown flowers on red-brown stalks from July.
- Sangria switchgrass: compact, 100 cm tall, fresh green ornamental grass with dark red stalks and brown-red panicles in autumn.
FAQ
On which switchgrass are the stalks blue?
There are three premium varieties that stand out with blue stalks. The switchgrass 'Heavy Metal' has already received several awards in perennials for its shimmering metallic blue foliage. The 'Heiliger Hain' variety is crowned with its bluish stalks with red tips in late summer. New on the market is the switch millet 'Dallas Blue' with blue-gray summer stalks and bright yellow autumn colors.
How fast does switchgrass grow?
Switchgrass can sprout until April in regions with mild winters or May in harsh locations. Then growth picks up speed. By the beginning of summer, a clump of leaves has usually reached its impressive height. From July it goes up again when the stalks with the inflorescences grow towards the sky. The speed at which switchgrass reaches its final height always depends on the local conditions.
Is switchgrass suitable as a privacy screen?
The wide variety of varieties offers several majestic switchgrass that are useful as privacy screens. The columnar switchgrass 'Northwind' is well known and popular with a growth height of up to 180 centimeters. The largest switchgrass goes by the name 'Cloud Nine' and stretches a whopping 250 centimeters towards the sky. At the seat on the balcony, the switchgrass 'Warrior' in the pot with a height of 150 centimeters ensures your privacy.
Is switchgrass toxic to cats?
No, switchgrass is not poisonous to cats. The stalks, flowers or seeds do not contain any substances that could be dangerous to your pet. Caution is advised when combining switchgrass with tulips or daffodils. The flower bulbs are highly toxic to cats even in small quantities.
When does switchgrass sprout in spring?
The sprouting of a switchgrass depends on the weather. After a mild winter and a spring without severe ground frost, the ornamental grass sprouts by mid-May. Wet and cold weather with delayed ground frosts postpones budding until the end of May/beginning of June.
Does switchgrass need a root barrier?
Planting with a root barrier is not absolutely necessary. Over time, the clump of leaves becomes wider and wider because the rhizomes spread underground. If there is a garden pond or lawn in the immediate vicinity, you can either use a rhizome barrier on this side or occasionally cut off the clump and its roots with a spade.
