Originally, almost all of the 500 or so species of *Passiflora* hail from Central and South America. Because of those tropical roots, these beauties are used to warm, sunny climates and usually won’t survive a typical winter outdoors. However, if you’re a fan of these exotic blooms, don’t lose hope! There are a few varieties that can actually handle a bit of a chill.
The Reality of “Hardy” Passion Flowers
When we talk about “hardy” passion flowers, we’re usually talking about plants that are frost-resistant under the right conditions, rather than being totally bulletproof. There isn’t really a species that is 100% winter-hardy in every climate, but the Maypop (*P. incarnata*) comes the closest. It can sometimes survive temperatures as low as -4°F (-20°C). Here are a few other varieties that can hold their own when the mercury drops:
- P. caerulea (Blue Passion Flower): down to about 5°F (-15°C)
- P. lutea (Yellow Passion Flower): down to about 5°F (-15°C)
- P. tucumanensis: down to about 5°F (-15°C)
- P. violacea: down to about 14°F (-10°C)
Getting Ready for the Cold Snap
To help your passion flower settle in for its winter nap, you’ll want to stop fertilizing the plant starting in September. As fall begins, it’s also time for a serious pruning session. You’ll want to cut the main shoots back so they’re only about 6 to 8 inches long, and try to remove the side shoots entirely. Once you’ve done your trimming, you can also start cutting back significantly on how much you water.
Winter Protection Steps
Once your passion flower is pruned and ready, it’s a good idea to set up some protection before the first frost hits. Your best bet is to apply a thick layer of bark mulch around the base of the plant to keep the roots cozy. You can also wrap the plant itself in garden fleece or burlap. With this kind of setup, a semi-hardy passion flower has a great shot at making it through a mild to moderate winter outdoors without any issues.
What to Do with Tropical Varieties
If your specific passion flower isn’t the type that can stay in the garden all winter, you should still stop fertilizing in September. I also highly recommend pruning these back as well—mostly because most of us don’t have a cool, bright room with 15-foot ceilings to house a full-grown vine indoors! For overwintering inside, try to find a spot that stays between 50°F and 54°F (10-12°C) until spring rolls around again.