|I bought a purple fountain grass and one place told me it will not come back every year but another told me it will. What can I do to make sure it will come back every year? One is in the ground the other is in a very large container. I'm in zone 5.|
|Pennisetum setaceum 'Rubrum' or purple fountain grass is only hardy into zone 8 and unfortunately there is nothing you can do to get it to overwinter successfully outside. The best way to overwinter it is in a cool greenhouse, but most of us do not have one of those at home.
If you want to experiment, you can try and see if you can keep it going indoors. In the fall, as it goes dormant, bring it into an unheated garage or similar area where it will not freeze but will stay cold. In early spring when it begins to try to grow, place it in a very bright but still cool location indoors and then as soon as possible begin setting it outside during the day when the weather turns mild. In the fall and winter, keep the soil just barely moist, watering only enough to keep it from going bone dry. In the spring when it begins to grow again, increase the watering slightly. Overwatering can cause it to rot while it is dormant, so this can be a bit tricky.