Why have bougainvillea if it doesn't flower? Pruning bougainvillea in summer, which is mid-season for this colorful landscaping plant, encourages another round of big bloom. Here's how I do it.
Pruning Bougainvillea In Summer (Mid-Season) To Encourage More Bloom
Let’s face it, why have bougainvillea if it doesn’t bloom? In terms of foliage and easy maintenance, there are landscaping plants I like much better. Show me the color I say! Pruning bougainvillea in summer, which is mid-season for this plant, encourages another round of bloom.
The one I’m pruning here is Bougainvillea Barbara Karst. It had been pruned into a hedge by the previous owners and showed very little or any blooms. I’ve lived in this house in Tucson for 2 years and have pruned it into a form which is pleasing to me. I need to prune it 3 times a year now – February, July and the end of November. The 1st is to shape and stimulate flowering and the last one in late fall is very light, just to clean up any dead or funky growth.
I’ve gotten comments like “why is my bougainvillea not blooming” or “my bougainvillea was blooming was blooming when I brought it home but now it’s not”. There are multiple answers for both (the most fundamental is that bougainvilleas need full sun and warm temperatures to flower successfully) but there are only 2 reasons I want to address in this post.
1.) Different varieties of bougainvilleas bloom more & for a longer period of time than others. My Bougainvillea Barbara Karst blooms more than my other bougainvilleas. It puts out a good bloom for 8 months & a much lighter for 3.
2.) Bougainvilleas go through a rest period after they bloom. For some varieties, it’s longer than others.
Good to know:
Bougainvilleas need full sun for at least 6 hours to put out their best bloom.
Pruning stimulates new growth which stimulates flowering. That’s why on older, taller bougainvilleas which haven’t been pruned in a while all the color is at the ends an/or at the top. You can see how I pruned my vibrant magenta/purple Bougainvillea glabra glabra in Santa Barbara to grow up and over the garage. It was much bigger and denser than this one and garnered many oohs and aahs when it was in full bloom. More pruning was required on my Bougainvillea glabra than on my Barbara Karst here in Tucson.
Good to know:
Bougainvilleas bloom on new growth.
My Felco #2 pruners. These have been my go to’s for almost 30 years now & I wouldn’t garden without them. I have the very same pair for all that time & haven’t replaced any of the parts.
Fiskars snippers – these are my go to’s for tip pruning the softer growth at the very ends.
Zenport multi-sharpener - Oh, how I love this for sharpening my pruning tools. It’s light, easy to hold, & does the trick in no time flat.
Gloves - As much as I love nature, I have no desire to have dirt under my fingernails!
Good to know:
Watch those thorns – bougainvilleas have a lot of them. Enough said about that! Also, be mindful of your eyes. Besides the thorns, a lot of dirt & “dregs” will most likely fall out when you’re pruning.
How I Pruned This Bougainvillea:
Starting with pruners.
Make sure your pruners are clean & sharp.
Take a good look at the plant.
I step back & look at the plant. Any dense spots? Sucker growth? Dead or weak growth?
Begin with the left side of the plant.
Starting with the left side (always have with this plant & who knows why), I take out any dense growth which usually is overlapping branches. You can start wherever it makes sense to you.
Remove the dead branches.
Take out any dead, weak or spindly branches along the way.
Don’t miss the parts that are touching the ground.
Anything growing too close to the ground comes out too. Foliage encroaching in the path of the garage door & into my patio dining area on the other side is pruned back also.
Once I get in pruning groove, the rest falls into place. This bougainvillea is now pretty much the way I want it but I did take off a few of the taller branches. I like being able to prune it without a ladder.
I cut just a handful (8-12) of branches back by half. This stimulates more inner growth to appear off those branches. If you’re going for a dense look in the middle, go for it. I like this bougainvillea to have a looser more open form which is why I go sparingly with this step.
I go through & tip prune the remaining branches. This pruning of the ends by 1/2″ – 5″ causes the flowering to be a bit denser which is a look I like. It’ll also cause more inner foliage growth so that’s why when after I’m done with the pruning, this bougainvillea looks a little thin. It’ll fill in a bit within the next few weeks.
This Barbara Karst of mine was putting out a lot of flower buds when I did this pruning. In 2 weeks time, it’ll be starting to put out a big bloom. Last year it was showing a lot of colors right on through to the end of November.
Good to know:
The flower color of a bougainvillea which changes as the temperature & heat changes. My Barbara Karst is a much deeper, more intense pink/red in the cooler months. In the hot more intensely sunny months, it’s more washed out. The lead photo was taken in March so you can see how much more vibrant the color & overall flowering is in late winter/early spring.
Good to know:
Let your bougainvillea be in the colder months. I didn’t prune it until early March (could have done it in late February but we know how that goes!). You don’t want to stimulate tender new growth only to have it freeze.
I love the location of this bougainvillea because we see it when driving up into the garage and also from the kitchen and patio. Dining alfresco with a backdrop of bright pinkish/red – so fine!
Nora Lee on Sep 13, 2018
This is a really helpful post. Thank you! I live in Ottawa, Canada, so I can't grow a bougainvillea outside all year but I have on in a pot that I bring in for the winter. Your detailed guidance on pruning will be helpful for me in planning its management for bloom next year.
Joy Us garden on Sep 22, 2018
Great to hear Nora! I've done many other posts & videos on bougainvillea which you might find helpful: https://www.joyusgarden.com/categories/#bougainvillea