Butterfly Bush

I planted some butterfly bush plants this spring. They came up and bloomed, got way bigger than I expected. And not the variety of colors I wanted, but the good thing, they came up!! Now it's fall, do I cut them back to the ground or what? I'm sure you guys can help me here. Thanks.

The advice I usually see is to cut them back in spring, but I'm not sure if it causes a problem to cut them back earlier. I would also mulch them really well for the winter--they're only hardy to zone 5 so I think they'll be pretty borderline for you (I think Sioux Falls would be zone 4b?) Even in zone 5 they can be borderline sometimes--if there's a lot of snowcover to insulate them then they are more likely to come back, but if there's not as much snow then sometimes they don't.

I should add--my comments were based on the assumption that you were referring to Buddleia davidii http://davesgarden.com/guides/pf/go/128/ It's probably the most common thing that's called butterfly bush, but there are others that go by that name too, so if this isn't the plant you were talking about maybe you could post some pictures of yours or post the Latin name of yours if you know it.

What ecrane said and...

We recommend to our customers (even in zone 7b) that butterfly bushes not be cut back until early spring. You can cut it back to about three feet safely in fall and then in spring you will probably be cutting back to one foot or lower because it will probably die to the ground and return from the roots anyway (if it survives the winter). Also, in general, you shouldn't do any late summer pruning of plants until their foliage drops off. If you prune a shrub before it's dormant it just wants to replace the foliage that's been removed and that new growth will get burned off as soon as the first freeze comes along.

I"m in zone 5a, and no Butterfly Bush has ever survived here in the ground over the winter. I have one in a large container that I brought inside an unheated GH for the winter. It survived, but it wasn't very happy this summer and hardly grew at all. I hope yours makes it through the winter. They're so pretty.

I also live in zone 5a, but I've had my Butterfly Bush for..well this is going to be its 3rd winter. I cut back in the spring. I have never mulched anything and granted it isn't a huge bush, but it blooms nicely every year so far. It has only ever grown to about 2 or 3 ft. high and about 3ft. around and I am sure they get much larger than that, but it fits in nicely where it is and does well enough. Good luck to you!

You're lucky then--you must have a slightly warmer microclimate or a more sheltered location for it, or else maybe you get more snow than some other areas in the same zone. I have family in zone 5a/5b and they often have trouble with theirs. When I was growing up there we used to get tons of snow and they'd always make it through the winter no problem, but now they don't get as much snow as they used to so some years they make it through and some years they don't. I think bubbles1918 is closer to zone 4 though, so there I would definitely recommend mulching, otherwise there's a good chance they won't make it.

I am in zone 4. And I have no idea the Latin name for any of my flowers. This one I got from Gurneys this spring and was listed as "multi-colored butterfly bush". They are only about 4' tall, long green bamboo like stems and frilly leaves all the way up to top, with tight little flowers (alot) at time. Bloomed for weeks and weeks. Now is done and there are seed pods turning brown with little cottony seeds that are floating away. No pictures, sorry. Maybe next year, we'll see. Thanks for you input. Always appreciated.

I think based on your description (particularly on the seeds) you may have Asclepias (often called butterfly weed) not butterfly bush. On Gurney's website they refer to it as butterfly flower mix http://gurneys.com/butterfly-flower-mix/p/71524/ They do also sell butterfly bushes (Buddleia) http://gurneys.com/search.asp?ss=butterfly+bush but your description doesn't seem to fit. If your plants are Asclepias, then I'm not sure whether/when you're supposed to cut them back.

Also as a side note, you may want to explore the Garden Watchdog before making purchases from mail order nurseries--sounds like you got lucky with Gurney's but they have quite a few negative comments so there may be better places to buy from next time. http://davesgarden.com/products/gwd/c/184/

Wow. I guess we should have asked a few more questions first. I swear, working retail I've heard pretty much everything that blooms referred to as a "butterfly bush" at some time or another. I should know better by now.

Now for my revised comments:
No, I wouldn't cut it back until spring because the stems can hollow out in winter and possibly get water inside them, then freeze the plant from the inside out.

If you have Asclepias tuberosa, (Butterfly Milkweed) you should have no problems overwintering it. It's a native prairie plant that grows in most states including South Dakota. I don't do anything to mine. It's planted way out in a prairie bed that doesn't get a whole lot of my attention. I used to burn the bed in the Spring to kill weed seeds and all the dried plant stems from the year before, but that's about it. Prairie plants start from scratch every year, not on the previous year's, above-ground growth. If you have a hybrid of some kind, then it might be more fussy.