How to prune a Buddleia (Butterfly Bush)? (photo attached)

[FlyingDuster]

I read somewhere that mid-march was the right time of year to prune it? And that it should be pruned back hard? But it is quite large and tree-like and am not sure how to do it? I like seeing the butterflies in the summer and don't want to kill it. Btw I need to cut the tree stump (in front) close to ground level and treat it with stump killer or something.

You wont kill it. Impossible

Cut down to 3 foot off the ground. It will be the same size as your picture by late summer.

F

Ours is about 8 feet tall and we chop it down to 3-4 feet tall , just leaving the thick branches. It grows back completely every year.

Another saying you couldn't kill it even if you wanted to - be brutal!

It looks like its on a single stem. I'd leave the "trunk" but cut every branch so it has one bud facing outward. Or just cut it all down to about 30cm of the trunk.

Last year I chopped ours down to about 20cm above the ground (at about this time of year); it was back to being taller than me by mid-summer. They grow back pretty fast.

Because it on a single stem I'd cut it all back to about 30cm above where it starts branching, to an outward facing but if you are feeling fancy.

Agreeing with everyone. We cut mine down literally to ground level last year. That did give them pause for thought but they had still regrown by the end of the year.

3 ft still leaves mine 10-15ft tall by the end of the year.

We cut ours down to the ground and it came back bigger than ever! You can prune them hard, they are impossible to kill.

You won't kill it. Cut it down as hard and low as you like, even to ground level, and you'll still have a sizeable bush by mid summer.

After a nuclear attack, there will only be cockroaches and buddleias thriving.

I cut mine to knee high each year and it's always a good 10ft by the summer.
They grow wild in gutters, they are really not divas.

I pruned mine one year to about 12", then a bit broke off so it was even shorter. Fella was pissed with me, he thought I'd killed it 🤣

The blossoms smell lovely so cut it short and they'll be nearer nose height rather than towering overhead. Makes it easier to deadhead too so you can get a second flush.

Cut it to the ground, take the branches to the green bin, by the time your bin is full it'll have already grown back to the size it was before.

Is it a nice colour?

Agree with everyone else - cut it back hard, it'll be fine.
I love buddleia - have a white one, a very dark purple (Black Knight) & a miniature pale purple one in a pot.

Love Black Knight, it's got a great intro. and lovely deep purple....panicles(?).

@FlyingDuster PLEASE DON'T use stump killer on the tree next to it.

Stump killer is poison which doesn't just kill the plant it is applied to, it leaches into the soil all around and kills anything else that has also has roots in the vicinity.

Agree with what other people say that you can chop buddleia back as drastically as you like. With yours, I'd trim it into a neat lollipop tree shape, to keep the existing look, which is quite unusual for a buddleia and rather nice.

Thank you everyone who took the trouble to reply. You're all in agreement and I'll follow the group's advice. Also I won't use stump killer on the stump in front. I'll chop it lower and paint some bitumen or something on the cut.

Yep, you’re hard pushed to kill these little buggers. I’ve pruned mine any time of year and it’s still here.

Mine was bought as a twig , and doing well . It's in a pot because I need it to fill a low fence space (and as they can grow in a gap in a brick wall then a large pot is luxury )

I'll cut it back this month and next year it can go in a bigger pot .

It's meant to be a Black Knight ....but it's magenta .

I cut mine back to about 3ft today. I want to keep it around 6ft in summer to provide privacy but it’s near the house so don’t want it too high either.

Mine always die after about 5 years. Fortunately they seed themselves and I usually keep one or two growing from cuttings in pots to re-plant.
I reckon it's our clay soil - they rot at the base. Buddleia globosa REALLY hates it.
If you are a butterfly fan and have several buddleias prune them in succession, leaving the last until mid April so you'll have good flowers all summer.

@pinkgown I only have one buddleia and get flowers from May/June to about October. I deadhead any that go over and it just keeps going.

Try cutting the stump horizontally, not slopping, and cutting some deep V shaped cuts across it, so water won’t drain and will accelerate the rotting.

Do as @Yamadori says re Buddleia. (In general, if it’s a tree question, do as @Yamadori says).