overwintering Pennisetum setaceum ‘Fireworks’


Good morning,

I have grown, Fireworks Fountain Grass, Pennisetum setaceum ‘Fireworks’ all summer in a pot on my patio. It still looks beautiful.

I would like to overwinter it. Online I am reading conflicting information on keep it in the dark, keep it by a window, water regularly, don’t water, cut it back, don’t cut it back.

If you could please advise me as how to overwinter this plant that would be great. I have put it in my east facing window and attached a pictures. The lighting doesn’t do it justice

I live north of Barrie and DO NOT have a heated garage and my cold room is only about 5 or so degrees colder than the rest of the house. I do have a dirt crawl space under my house but would worry a bit about mice?

The windows in my house are fairly low light areas as we have alot of trees and the south facing windows do not have any spaces for plants.

I appreciate any advice you might be able to provide.


(PS I realize they only cost about $14 to buy a new one each year but it would be really nice to have a bigger plant next year that I could split for multiple pots or even to accent in the garden.)


Thank you for contacting Toronto Master Gardeners.  Your Fountain Grass is a beautiful plant.

Pennisetum setaceum “Fireworks” is a variegated form of purple fountain grass is native to Africa and is considered a warm season grass that in Ontario’s climate, is considered an annual.  It is a pink and white variegated purple fountain grass that reaches 24 – 30 inches in height, preferring full sun.  It is successfully grown in containers and is particularly showy in the fall landscape.  Warm season grasses thrive in temperatures in the mid to high 20s and remain attractive well into the fall.  Normally, these plants are not expected to overwinter in the garden when temperatures consistently go below freezing.

You are correct that there is conflicting advice on overwintering this annual grass. Two reliable horticultural sources, the Missouri Botanical Garden’s and the University of Wisconsin-Madison Master Gardeners both advise that the plants can be cut back and overwintered in a greenhouse or cool sunny location. The soil should be kept moist, but not wet as overwatering can cause root rot.  In the spring, gradually move the plant outdoors when all danger of frost has passed.  You can refer to these articles for more information.

http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=270935 and https://wimastergardener.org/article/pennisetum-fireworks/

It seems that you may have some difficulty with this method if your house has limited light especially in winter.  Many sources do indeed simply recommend purchasing new plants in the spring so you may have to resort to that, but if you can find a suitable place, it may be a good experiment to try to overwinter your plant.

Good luck!