Hailing from South America, Bougainvillea (boo-gan-VIL-lee-uh) is a popular genus of somewhere between 4 and 18 (depending on whom you ask) species and over 300 cultivars.
These wonderful evergreens from the Nyctaginaceae family are cherished for their sharp thorns, bright flower bracts, and heart-shaped leaves.
Bougainvillea plants are known for not being fans of the cold, despite sometimes surviving a freeze at 30° degrees Fahrenheit.
Despite being decently large and shrublike with specimens ranging from 3 to 39’ feet tall, they’re very popular as container plants.
This fact means you can enjoy a bougainvillea all year around, once you know how to properly overwinter it.
How Do You Care for a Potted Bougainvillea in Winter?
There are two basic rules to overwintering a potted bougainvillea plants that can also apply to humans on vacation:
- Find a pleasant vacation spot (for the winter months)
- Let them sleep in.
In other words, choose an indoor spot that matches their outdoor needs and cut back on how much attention you give them.
That Indoor-Outdoor Lifestyle
One of the biggest mistakes gardeners make is to plant a bougainvillea in spring, then transplant it to a pot for winter.
This can stress the plant severely and can do almost as much harm as leaving it in the ground.
Instead, there are two ways to keep your plant outdoors for the warm weather that won’t harm them, and both involve containers.
The first method is the obvious one:
Sit the container on a patio, porch, or another area when the plant is outside. Bougainvilleas are popular in Florida.
When the weather cools off, you can simply move the plant inside to a sunny spot until spring.
The second method involves a bit of visual trickery.
Dig a trench where you want the bougainvillea vine to be and line the sides so the walls won’t collapse, leaving the bottom bare.
Next, gently place your bougainvillea – pot and all – into the trench.
Fill the gaps with bark or lava stone, allowing a little bit to cover the edges of the pot.
The bougainvillea will appear to have been planted, but can easily be lifted out of the trench to overwinter, still safely in its pot.
Before Checking In
Before you bring your bougainvillea indoors, it needs a physical.
Check for any signs of disease or infestation and be sure to treat these issues before exposing any indoor plants to a possible contagion.
Regular neem soil soaks and/or foliar sprays can greatly reduce the risks of bugs and fungal issues, even when the plant is kept outdoors.
When and Where to Bring Bougainvilleas Indoors
Bougainvilleas prefer full sun and temperatures of 60° degrees Fahrenheit or higher. You may choose to bring one inside at any point when the temperature slips below that.
Try to have it inside prior to the first frost in any event, as containers won’t insulate as well as the ground and even a light frost will be much nastier on a potted bougainvillea than a planted one.
The plant will need a good “vacation spot”, so choose a room that gets good winter sun exposure.
Ideally, you’ll want to keep the plant where it can get bright, indirect sunlight for as much of the day as possible.
Some direct sunlight in the morning or evening can also be good.
While it will do fine in normal room temperatures, an overwintering bougainvillea will be happier if you can keep it in a spot where the temperature stays between 45 and 55° degrees Fahrenheit.
Additionally, the winter spot should be free of drafts.
For these reasons, some enthusiasts will actually overwinter their bougainvilleas in a garage or shed that has insulation and windows.
Avoid Fertilizing in Winter
Winter is a time when your bougainvillea wants to take a break from the hard work of growing and blooming, so the last thing it wants is a heady meal.
Avoid fertilizing during this period, and give it water sparingly using the soak-and-dry method.
You’ll find the plant needs less moisture and drinks less while overwintering, naturally resulting in longer periods between waterings.
A light pruning in winter can help encourage new growth come early spring, but this may also be done at the end of winter.
Avoid any heavy pruning if you see yellowed leaves, as this could be a sign of frost damage and too much cutting back could do more harm than good.
That said, a healthy plant may need a major haircut before you can bring it in to meet the family.
It’s also normal for some minor loss of foliage during the winter, so prune away any browning leaves as you spot them to help your plant conserve its energy.
As you can see, it’s much easier to remember what you need to do if you imagine your bougainvillea is taking a much-needed vacation.
As an evergreen, it will still shed a bit of foliage, but does not actually go dormant like deciduous plants do.
The key is to give your plant some space, letting it rest up and gather its energy for the next growing season.