If you going to just let them grow and not manage them, then I would say at least 5 feet from the sidewalk.

Certainly I would manage them!!

Really, what do you mean by that Ben? I always cut mine back to virtually the ground in spring anyway, and then deadhead the flowers. Not much to management actually.

Susan

"At least 5 feet from the sidewalk" is good advice. Some B. davidii near here are about 2 feet from the sidewalk and that walk is unusable from mid-summer on.

Perhaps this butterfly bush does not grow as large in your locale; local nursery people should know.

I had the misfortune (ok, the stupidity LOL) to plant my milkweed too close to the BB. Last year the bush went up and OUT and DOWN, and the poor milkweed thought the lights went out.

Sooo..this year, I'm pruning and pinchpruning the thing wayyyy UP before allowing any shoots to go that direction. If this doesn't work the milkweed is going to have to move and I'll put something that likes shade where it used to be.... :)

5 feet from sidewalk....pretty good idea. You can always put some shadeloving shorties closer.

We have gravel paths throughout the sun-portion of our one-acre butterfly sanctuary and have 18 butterfly bushes situated along these gravel paths. The butterfly bushes are 3-4 feet off the edge of the gravel paths. I cut them back each year in early spring and trim any branches that get too close to the paths during the summer/fall. This approach allows us and visitors to see butterflies very close to the path and keeps the butterfly bushes from impeding walking on the gravel paths.

mike

I have a 10yo that's maybe 4' from the sidewalk. Even though it doesn't interfere with the sidewalk, it gets heavy activity from the carpenter bees. It just got me wondering if they're partial to the white buddleia's, since I barely see any on any of my others (Pink Delight, Royal Red, Black Knight, a lilac). If I can't even get near it to prune it, I pity the people that walk by it; those things are nasty...

I think Ben's advice was sound....many people do not know how to keep a butterfly bush within bounds by annual pruning and occasional clipping. It sounds like Mary does, but Ben's advice is right on the money. Once a plant becomes a nuisance, it needs to be removed. Best to plant so that issue can be avoided entirely.

I think the point was missed, but never mind......

Susan

Now that I read all of this, it got me to thinking that I did a dumb thing when I planted my butterfly bushes in the garden last year, but I'll get to that. I put them on the outside section on the one side of the garden on the east side, thinking that would be a good side to put them on so they would only shade the nearby plants only a small part of the day. I used landscape cloth and mulch and planted them five feet from one another, allowing room for them to grow. Well, dummy me didn't think about that they'd grow just as much on their east and west sides and their north and south sides and I only have them two feet from my brick path. I see that already it will become a problem this year because last year the bushes made their way over to the edge of the path. This year they will most likely block it and I won't be able to walk down that path. As much as I hate to think of the extra work on top of what I have already made myself, I think the best thing to do is to move them. That means moving the mulch, cutting the fabric slits bigger to get them out, digging them out, replacing them with other plants (which means cutting slits in other places according to how far apart to place the replacement plants), putting the mulch back on, and finding a new location for my butterfly bushes. So right after I read on here that people don't recommend using landscape fabric, I'll have it in there anyway when I replace the butterfly bushes with some perennials (not bushes). Of course, I guess it will match the rest of the garden then because when I did the garden I put in landscape fabric thinking that would be best to keep the weeds down. After all that work last year and now I'll end up redoing half of it because of removing the butterfly bushes and some other plants that don't suit me because they didn't attract any butterflies. Actually, out of the six sections, I'm only totally satisfied with two, the Purple Coneflower section and the Butterfly Weed section. Yes, I have to take those butterfly bushes out of there. I had to do it this spring because I already have enough to do with everything else, but if I don't do it in the spring, they'll overtake the path. Arg!

Cathy,

Maybe it would be possible to trim them????

Elaine, I don't know if it would or not actually. I cut mine down to about a foot tall in the spring and then let them go from there. I just didn't know if it would hurt them to trim them. I'm not sure when or how often to trim and if trimming would affect the blooming any.
Cathy

Trim will delay bloom on that part of the plant, but it also helps to extend the bloom season if you do part of the plant at a time during the year....