Depends on what you want. If you cut it back by 2/3 it will not be as tall and you get more flowers lower down. If you only cut the top 1/3 off the flowers will be higher up on the shrub. I usually cut mine back to about 8-12" from the ground around late April or early May, as new budding becomes apparent, but it depends on your zone. I'm also zone 5/6,if that helps. You won't kill anything by pruning earlier.....you may just need to go in later and prune more if some of the branches don't come back. Hope this helps. Adonis is supposed to be a smaller cultivar so you may not need to prune as severely??

Hi,
I wait until I see new buds growing in the spring and prune above them. Many years, that is only a few inches above the ground, so I don't think you will have to worry about how much to leave, you will be wishing there is more still alive. : ) Don't worry though, they bounce back and get quite large even after a tough winter.
Remy

Ditto with the others. I also cut back in late April as much as possible, though some of my buddleia are more than ten years old and I can only remove the top half without resorting to power tools. Whether I prune the top half or go down to about one foot above the soil, they grow tall and bloom until November. Good luck & enjoy.

I have grown them for many years (z-5)and was told to cut them down in the spring (when I notice them just starting to leaf out) to about six inches from the ground. They always grow and do very well.

We're in approximately the same zone, and I prune in mid-April. Any severe weather is typically done by then. I cut mine down to about 1 foot because they can really put out a lot of new growth. My white butterfly bush gets about 8 feet tall whereas my purple ones tend to peak at 5 or 6 feet. Mine don't really hit their stride until July.

It really depends on the cultivar, so if you're not sure then I'd say err on the high end. Remember, you can continue to prune these shrubs throughout the summer if you find they're getting too larger. Sometimes I take a hedge clipper to them if I want to prune off all the dead flowers or shorten a branch here or there. They will reward you with more growth and blooms. Just remember to stop any radical pruning before fall.

Don't be discouraged if they sprout quite late. Do wait until very late before giving up on one NOT sprouting. Mine did not start sprouting until July!! I had pulled one up, thinking it was dead, when I noticed new roots, so I replanted it. They took quite a while to recover from that yanking out. I planted a bunch of new ones in different locations, various colors. I enjoy them a lot.

Keeping the flowers cut off after they turn brown, does encourage growth and reflowering.

I have put rose cones over the new butterfly bushes I put in last summer. This is so the wind in that location doesn't kill off the tops like last winter. Hoping to get earlier sprouting, so they have more summer growth and earlier flowers.

I also prune mine in April, take them down to about 18-24 inches. They are mostly older bushes, have very heavy branches. Even with late sprouting, they get fairly tall, about 6ft, some shade.

Butterfly bushes grow very easily from cuttings too, so if your pruning off live material, you might consider sticking those cuttings in a pot of ProMix, water them(and keep moist) and cover the pot with a plastic top or bag to keep moisture in.

Viola! New butterfly bushes in a matter of a couple months! :)

I just bought a 'White Profusion' at a nursery bargain bin yesterday, where the plants are kept in an outdoor but protected spot. There is still lots of green leaves and live branch material on the butterfly bush and I'm going to take cuttings and start them in my greenhouse.

I have had a butterfly bush quite a few years too. I moved mine from the front to the back two years ago. It must be in a more sheltered location, because I get new buds all along the branches up to as high as four feet. I am in zone 6a. So where I normally would cut mine back to less than a foot, as some have suggested, when it was out in the front, the past two years, I made a decision to let it grow as much as it was able to. I just trimmed back the branches on it to about four feet high. Both years, it has retained a vase shape and bloomed fine, topping out at about 7 feet.

Next year, I am thinking I will go back to a lower height, just to give it blooms lower on the bush and maybe a little less height and fresh branching.

pm2

In zone 5 they will die right down to the ground. I cut back to a couple of inches in spring and they always come back eventually and end up seven feet high. The third year it's a good idea to remove the one year old stubs.

Hi everyone. Hope someone can help me. Alabama ~ Zone unknown. My bushes are approximately 4-5 foot tall.

This is my first year having butterfly bushes. I had long streamers (approx 16 inches) of beautiful blooms. The blooms died, and underneath them, I have blooms of approx. 2 inches.

Question: How and where do I cut the dead blooms off so new growth comes back this flowering season. I would prefer my long streamers come back, and not the 2 inch blooms.

Thank you in advance for any help.

paintballermom, cut off the dead blooms just above the next set of leaves, or further down the stalk if you want to shorten them a bit, but just above a set of leaves. If you get behind, you will often see new blooms emerging from the point between the stem and a leaf. You can cut just above that and the bloom will come on out and probably be larger as a result of the old bloom being gone. The bush is trying to set seed, which is the life goal of all plants. If they achieve it, they stop flowering. Cut off the seed-making heads (dead blooms) and the plant gets back to work.

Thank you for your response. I was able to understand it fully.

This spring, I cut back my "Black Knight" to about 6-12 inches from the ground, which is what I usually do. It is a vigorous grower, and reaches 7 feet by the end of the season.

The 'Pink Delight' however, I cut back to about 3-4 feet high, similar to the way that Prairiemoon2 described. This is because it had SO many buds of new growth coming out much higher up on the stems. It is now about 7 feet high, and has a very nice shrub-like shape. That's the first time I've cut one back like this, and it seems to have worked very well for that particular plant.

And yes, I deadhead Buddleia religiously through the season, to promote more blooms and frankly the dried up flowers look ugly.

Pieheart, I have many buddleias and would love to know how yours did, pruned center higher. Would you let us know? Thanks.
Sunny

If I remember I will take some pictures tomorrow. They aren't blooming yet, but they are covered in lots of buds.