Ah, bougainvillea. People seem to either love this plant or hate it, and their feelings are usually based on whether or not they’ve ever had to take care of one before. They are, after all, gorgeous when they’re in bloom, putting on a brilliant and eye-catching display of color all summer long. Trouble is, once they’re established, bougainvilleas can grow like a weed, sprawling out 15’ or more over the course of a season and requiring frequent trimming in order to keep the vine in check. Oh, and did I mention the thorns?
Because bougainvillea grows freely along the side of the highways in Southern California, a lot of people assume that it should do just as well here in Vegas. After all, we’re only a few hours away by car, right?
It’s important to realize, however, that there’s a decent little mountain range between us and Southern California, so our climate is substantially different than that of San Diego or L.A., where people put on a jacket and scarf when the temperature dips below 60°F.
Ok, to be fair, I’ve seen that done here, too.
Nonetheless, Las Vegas does get colder than Southern California, and bougainvilleas have an intense dislike for the cold. These plants have an especially sensitive root system, which means that until they’re well-established, there’s a good chance that they’ll be damaged by a hard frost. That doesn’t mean that they can’t be grown here, but it does mean that you’ll want to plant them in the right spot and take a little extra care for the first couple of winters they’re a part of your garden. So let’s get into the specifics of how to grow bougainvillea in Las Vegas.
Where to plant a bougainvillea:
A lot of people don’t realize that bougainvillea can take about as much sun as you can throw at them. In fact, it really needs at least a good half-day of sun in order to bloom, and most varieties will do just fine with a blast of all day Mojave sunlight beating down on them. The only exceptions to this rule are those varieties that bloom in lighter colors or that have variegated leaves. They’ll do best in an area that gets a lot of morning sun and that’s shaded in the afternoon.
As previously mentioned, what no type of bougainvillea likes is cold weather, which means that a south-facing wall with all day sun exposure in the wintertime is really the optimal place for them. You might not think it would matter, since the plant will be dormant and look fairly well dead, but that wall will reflect the warmth from the sun onto the ground in front of it, right about where the roots of your bougainvillea are located. A wall will also act as a shield for the plant against the prevailing cold north winds of the winter months, protecting the roots even further.
The next best place for a bougainvillea would be on a west-facing wall. If you don’t have these conditions in your garden, you may want to think about planting in a container, so that you can move it inside for the winter. Bougainvilleas will do just fine in a pot, given that it has good drainage and plenty of room for its roots to grow.
When to plant a bougainvillea:
The best time for planting a bougainvillea in Las Vegas is in the spring, after the last chance of frost, which falls in the middle of March. Get it in well before we start to get really hot in late May, so it can ease into the scorching heat of the summer sun. Remember too that the earlier in the season you plant, the more established your bougainvillea will be when the cold hits.
How to encourage established roots:
The sensitive root system of bougainvillea should be treated with care, both during planting and afterwards. If you’re planting in the ground, be sure to dig the hole wide and then amend the local soil with a richer planting mix. You’ll want to add in a good starter fertilizer too, since the soil here is effectively nutrient-free. For pots, use a well-drained potting soil with a built-in starter fertilizer to get your plant established.
In order to disrupt the roots as little as possible, use a box cutter to slice away the bottom of the plastic container that the bougainvillea comes in. Place it in the hole, and then gently slide the rest of the container up over the plant. Fill in using the amended soil and fertilizer mixture, being careful that you aren’t disturbing the roots as you go.
Once you’ve got the plant in the ground or pot, it’s a good idea to apply a transplant shock preventer. This will help to soothe the roots and mitigate stress on the plant, in much the same way that a strong vodka tonic works on some people I know.
The way you water your bougainvillea will have a big impact on its health and can be a major factor in whether or not it comes back after the winter. It’s important that you water deeply and infrequently, allowing the top layer of soil to dry out between drinks. These plants are, by nature, fairly drought-tolerant, and they won’t like having the top layer of soil wet all the time. Watering a little bit all the time will also encourage surface roots, which can mean death for a cold-tender plant in Las Vegas. Send the water down deep and the roots will follow, eventually making it to a point in the soil where the temperature is consistent year-round.
How to protect a bougainvillea from the cold:
Most people assume they’ll need to wrap their whole plant in burlap when the cold weather hits, but that’s actually not the way to protect a bougainvillea from the cold. Instead, just head out in October and wrap some burlap around the base of the plant in order to protect the roots.
Bear in mind that you’ll only need to do this for the first couple of winters, since once it’s properly established, the roots will be stronger and deep enough for the plant to take care of itself.
How to get an established bougainvillea that comes back year after year:
Now, I have to tell you the number one mistake that I see people make every single spring when it comes to bougainvillea (and a lot of other heat-loving plants, for that matter). After they’ve gone to all the trouble of planting their bougainvillea with such care, watering it precisely so, and protecting it from the winter cold, what do they do to kill it in less than a day?
They rip it out of the ground in April and bring it back into the nursery for a replacement.
And then we have the following conversation:
“It’s dead. The cold killed it. It’s not coming back,” they say, holding an uprooted wad of sticks in their hand.
“It wouldn’t have come back yet. It’s not hot enough,” I reply, sweating from the heat.
“It’s 90° out! How is that possibly not hot enough??” (Yes, we often get to 90° in April in Vegas. Which, to be fair, does seem hot, if you’re not a bougainvillea).
These plants will not come back in April, or possibly even May, for the first couple of years. They want it hot, and I mean, really, really hot, before they’ll even think about waking up from their winter sleep. One thing that you have to be aware of when you’re gardening in the desert is that while the daytime temperatures may be hitting the upper 80°’s and lower 90°’s, the nighttime temps are probably still somewhere in the upper 50°’s and 60°’s. That’s jacket weather for these plants. Remember, they’re from L.A.
After all the hard work you’ve put into getting your bougainvillea settled in, all you really need to do is be patient with it in the springtime. Oh, sure, hit it with some fertilizer in late April or early May, but otherwise, just sit back and wait. When it does start to come back, probably in late May or early June, it’ll start from the base. At first it might look like you’re going to have a pathetic little shrub all summer long. And then, all of the sudden, when the 110° heat kicks in, that vine will take off like nobody’s business and you’ll have one of the prettiest, thorniest weeds that you ever did see.