If you’ve ever seen the blooms of a Brugmansia (broog-MAN-zee-ah), you’ll know why they’re called Angels’ Trumpets.
These spectacular plants are now extinct in the wild, but all seven species, two natural variants, and countless cultivars are thriving in gardens worldwide.
Being tropical plants, angel trumpets aren’t very cold hardy and will need some special care to make it through the winter.
Tips on Angel Trumpet Winter Care
While it’s generally best to bring them indoors, you can leave a Brugmansia outside after cutting back the stems and protecting the roots.
Its general needs will be much lower during this time, as the plant will be dormant until spring.
When to Winterproof Your Angel’s Trumpet
This can be a little confusing for many people, as you actually want to wait until just after the first frost to winterize the plant.
This first light frost will cause some initial leaves to dieback and tell the plant it’s time to stop growing.
Indoor plants won’t get this signal, of course, so you’ll often be able to enjoy the plant all year long.
Likewise, Brugmansia are known to be more or less evergreen in the warmest zones and may require no winter proofing at all in places like Florida and Texas where even light frost is rare.
Do You Need to Take Angel Trumpet Plants Inside?
This is an important consideration which varies based on the type of Brugmansia species, cultivar, and hardiness zone.
Plants in the warm group are less cold hardy and will need to be brought indoors if you live in zone 9, while those in the cold group (and more cold-hardy cultivars) can handle being outdoors down to zone 7b.
As mentioned before, you may need to bring the plant indoors in the lowest favored zone (i.e. 9b for warm group and 7b to 8a for cold group).
However, in most cases, you can safely keep the plant outdoors unless you’re expecting particularly harsh conditions.
The rules are a little different for potted specimens due to their lower insulation (unless you have the container submerged in soil, of course).
To tell if a particular potted Brugmansia needs to be brought indoors, consider the lowest zone that species or cultivar can grow in and add two full zones.
For example, a potted cold group Brugmansia that can grow in zone 7b in the ground must be brought inside if you live in zone 9a or colder.
Winterproofing Outdoor Plants
This can be a surprisingly easy task, especially in warmer zones.
If your Brugmansia is able to remain outdoors but you’re in a cooler zone, you may wish to cut the trunks back to 6” inches or so from the ground at a 45° degree angle.
This will help the plant conserve resources and help protect it from frost damage.
In zones 10 to 12, this step may not be necessary, but you may wish to do so anyway for fuller growth next spring or to propagate new plants over the winter.
Give your plant a nice warm blanket of mulch a couple inches deep to keep the roots from getting frosted.
General Winter Care for Indoor Plants
For plants grown indoors all year, the only major changes are cutting back on the water and not feeding the plant at all throughout autumn and winter.
You may wish to move the plant to a sunnier spot or leave it where it is.
Keeping the room that it’s in about 10° degrees Fahrenheit cooler than normal will help the plant conserve more energy.
For example, if the room is normally 70° degrees Fahrenheit during the day and 60° degrees Fahrenheit at night, aim for 60° degrees Fahrenheit during the day and 50° degrees Fahrenheit at night.
For outdoor plants overwintering inside, you’ll want a cool, dry spot to store them, preferably with low light.
A garage or basement is generally ideal.
Aim for a temperature of 30° to 45° degrees Fahrenheit to ensure the plant stays asleep until it’s time to move it back outside.
Don’t feed the plant and only water it often enough to keep the roost just slightly moist (usually when the soil is dry about halfway down the pot).
When to Move Back Outdoors
Once the final frost of early spring has passed, you can take your Brugmansia back outside.
Note that a late frost may kill off some new growth, but the plant will generally have no problem growing back from the roots.
You may also begin fertilizing and watering normally at this time.