Known by the scientific name Panicum virgatum, switchgrass is a perennial plant also called “Panicum”. With nearly 500 species, switchgrass is a member of the Poaceae family (formerly known as grasses).
Native to North America, switchgrass can grow up to 4 to 5 feet tall. This ornamental grass flowers between August and October. Depending on the variety chosen, switchgrass has foliage in a variety of colors that allows it to stand out from all the other plants in the garden.
Very resistant, switchgrass can survive all climatic hazards. Its large, upright clump offers a decorative touch in any season, whether it’s windy, rainy or snowy!
How to plant switchgrass?
Thanks to its great adaptability, switchgrass can be easily planted in any type of soil. It is best planted in the spring or just before spring, from March to June.
Where to plant switchgrass?
Switchgrass will do well in full sun, although planting in partial shade is also possible. However, if it gets maximum sun and light, it will take on a more beautiful silhouette and better colors!
Switchgrass is a versatile plant, able to adapt to different situations. It appreciates fresh and fertile grounds, but can also be installed very well in a poor and dry ground, stony, even sandy. Its foliage will even tend to take more beautiful colors in this type of substrate.
In rich soil, switchgrass may tend to flare, while it will adopt a more rigid and compact form in poor soil. The most important thing is to install it in a draining soil, where water can easily infiltrate.
Switchgrass also has a preference for calcareous substrates and likes deep soil.
You can also plant switchgrass in pots, but choose the less bulky varieties (‘Cheyenne Sky’, ‘Kulsenmoor’, ‘Sangria’ …) and a large enough container because they are imposing grasses that have a well developed and deep root system.
As switchgrass has a good hardiness, it can be installed in regions with a cold climate. It is also not very sensitive to strong winds and tolerates sea spray well.
Switchgrass are quite tall plants: don’t hesitate to install them in the background of a bed, behind lower plants. They will help to structure it, and will constitute a beautiful, very natural backdrop, which will highlight other more colorful blooms. We also advise you to plant them in groups, to create a more beautiful effect!
When to plant switchgrass?
You can plant them in spring (April-May) or in autumn (September-October). The best time to plant is when temperatures are mild enough, outside of periods of frost or high heat.
How to plant switchgrass ?
It is preferable to respect a planting distance between 2 and 3 feet, depending on the variety grown.
- Place the root ball to soak in a basin filled with water
- While it is rewetting, dig a planting hole at least twice the size of the root ball. It is best to loosen the soil well, to make it easier for the plant to establish itself, as switchgrass has roots that go deep. You can add some gravel or coarse sand to improve drainage, especially if your soil tends to retain water.
- Install the plant in the planting hole, then replace some substrate around it and pack it down. Avoid burying the base of the stems, but make sure it is level with the original pot.
- Water generously.
- We advise you to install an organic mulch around the clump (dead leaves, RCW…).
It is best to continue watering in the weeks following planting while the plant is well established and developing its root system.
You can also plant switchgrass in a large pot or tray, using a draining substrate. However, it will require a little more watering and attention than if it is installed directly in the ground.
How to plant switchgrass in a pot?
Prefer a container with a porous material to avoid excess water and heavy enough to avoid tipping because the tall silhouette of switchgrass offers a grip to the wind that can make the pot tip over. Avoid pots with tight necks that make subsequent repotting difficult.
Check for drainage holes and place a layer of clay balls at the bottom of the pot. Fill with a substrate made of equal parts of garden soil (or rose potting soil), perlite and potting soil.
How to maintain switchgrass?
In the ground
Thanks to its tenacious character, switchgrass is very resistant to diseases and parasites. However, it can be affected by rust in case of abundant humidity. If this happens to your perennial, remove the damaged parts as soon as possible.
To improve growing conditions, add fertilizer 2-3 times a year. If you plan to grow switchgrass in a pot, it is important to keep the substrate cool and to water only when necessary.
During the winter season, wrap the pot with a veil to protect the root of the perennial plant from the cold. The cleaning of the switchgrass, as for him, is done just before the restarting of the vegetation.
Keep the soil cool, without excess, during the whole vegetation period. Limit watering in winter and remove saucers. Move the pot closer to the walls of the house to avoid excess water and draughts. In cold climates, protect the roots by wrapping the pot with several layers of non-woven fabric.
Fertilize once a month from April to August to encourage flowering.
Re-pot in early spring, every 2 to 3 years depending on the development of the switchgrass, and reseed in between.
Remove inflorescences as soon as they are no longer decorative.
Wait until the end of winter, as soon as the new vegetation starts, to cut back the dried out culms. Cut back to the new growth and finish with a manual cleaning by cutting at the base the dry leaves and stems.
Diseases and pests:
Switchgrass has good disease resistance, although it can be affected by leaf rust in hot, humid summers.
As for pests, aphids can weaken the plant if they are too numerous.