Most butterfly bushes already have quite a bit of new growth. Not far removed from being "weeds", they are very forgiving about how they're pruned, altho I prefer to prune them in spring after I see new growth appearing. In zone 8, they rarely need to be mulched in winter. I would leave it alone and see what it does.

Thanks Patrick, any idea on how long I should wait?

My DH chopped one of mine down last fall because it was in his way re-siding the house and I'm sure it is dead. It was one of the smaller ones 'Purple Emperor'. No signs of life at all.

I normally hard prune in spring. I have 'Peacock' in a pot and it has lots of new growth already. I liked the darker purple color better though. :(

Usually by March new growth of Buddleja davidii is well under way.

This species is no longer almost a weed in this region - and should no longer be planted. I have even seen it growing on the face of a building in downtown Tacoma. Any partly barren place is liable to sprout numbers of them now, each plant produces very large numbers of tiny seeds that apparently really get around. Rock walls, dry river beds, road sides, edges of parking lots, alleyways, building foundations, sidewalks...there they are.

The standard practice is to prune butterfly bushes in February after any chances of a hard arctic blast are pass. If you prune down to the base, it will take longer for leaves to appear. I had a hard December with four days of 12º F, and three weeks of below freezing weather. My butterfly bushes went deciduous this year and are just now putting out leaves. In 1990's arctic blast, which was much worst than this winter's blast, I lost all my butterfly bushes. All the butterfly bushes in the area died that year.

Criminy!! Buddleia is hardy to -20F (zone 5), so there should be NO concerns about winter hardiness west of the Cascades. We've yet to experience any "arctic blast" that came close to those temps. Hard pruned buddleia may be later to leaf out than those left unpruned, but in this area, they ARE weeds and will grow regardless of what conditions Mother Nature throws at them.

The two already existant in my new garden have been in leaf since early January and are already setting flower buds. Their removal is at the top of my list of garden chores for this coming weekend!

I've seen that too with Buddleja - cut them back hard in the fall and a hard freeze will kill them. Cutting back in the spring never seems to be a problem. Eucalypts in our climate have this same issue. I wonder why?

With so many cool Buddlejas out there, let's take care not to spew dislike towards other species besides B. davidii and its non-self-sterile cultivars.

You know, I would have thought that Buddleia davidii would be totally hardy for Western Washington with that zone 5 rating, but the 1990 freeze took them all out, even the ones along the road. It froze the whole month, ground rock hard for most of it and temperatures in the low single digits. Maybe if I had mulched around them they might have survived from the roots.

Just because a plant is rated for a colder zone in its native habitat doesn't mean it is hardy in a warmer zone else where in the world. There are a lot of various factors that affect a plants ability to survive. Summer heat, or the lack there of like in Western Washington can cause a plant to die at far warmer temperatures than they have survived in their native location. The palm tree Sabal minor is rated zone six in SE United States, but it freezes out in Western Washington's zone 8a because they need heat in the summer to produce the sugars to get them through the cold winter months in their native habitat. Western Washington's summers are cool, and our winters are cold and wet. A double whammy for the plant.

So maybe because our summers are cool and when we get a zone 7 winter, the butterfly bush hasn't been able to store enough sugar to get it through that type of winter here. We'll see when we get that type of winter again.

Correction: 'Adonis Blue' is the one that I believe is dead, not 'Purple Emperor' There are no signs of life at all.

It is five years old and I have no seedlings. Actually, I have no seedlings from any Buddleias. I did rip out 'Black Knight' ten years ago because it was a lot bigger than I thought it would be but never any seedlings.

Ian, Ciscoe says that much of the energy in roses are stored in the stem not the roots, so that is why you trim them back in late winter/early spring when the weather warms. That might be why butterfly bushes do better being trimmed in the same time period.

Last year I thought mine was a goner after that brutal December we had the year before. All the top growth died but it sprouted from the roots months later, I think in late May or early June. So it's not a given that it's completely dead.

The only one I've ever grown is 'Lochinch' and it's a bit less hardy. Last year was the only time in 20 years it's ever been set back like that, though.

'Lochinch' is a hybrid rather than a pure Buddleja davidii. The general behavior is for trees and shrubs to store energy in both stems and roots. With roses in particular, since these are cane growers that renew from a bud head, if there was any kind of shrub that stored nutrients more in the roots than in the stems it would be a one like this.

Another cane grower, Himalayan blackberry is supposed to be sprayed with glyphosate in the fall because nutrients in the canes are being sent down to the bud head at that time. The herbicide taken in through the leaves is expected to join the procession and concentrate in the bud head, killing the initials for next year's new canes.

What is supposed to be wrong with hard pruning of shrubs that may die back in winter is that the frost damage starts at the ends of the stems. The thinking is that the longer the stems during a dying back episode, the more stem will be left afterward.

Unless people living in Asian hinterlands have been making USDA Hardiness Zone assignments the one used here in the US for butterfly bush is based on experience with it cultivation, on this continent.

Other Garden Web chatter has tended to settle on it becoming marginal in USDA 6 (back East).

Butterfly bush is a Class B noxious weed in WA state.

"Class B noxious weeds are nonnative species whose distribution is limited to portions of Washington State.

Species are designated for control in state regions where they are not yet widespread. Prevention of new infestations in these areas is the primary goal.

In regions where a Class B species is already abundant, control is decided at the local level. Containment of these weeds is the primary goal so that they do not spread into un-infested regions."

Here is a link that might be useful: Class B Noxious Weeds

This last winter I cut my butterfly bushes back to only 2 feet tall or less as I do every year. Most came back strong as usual. But one of them (not sure of the variety although the leaves are slightly variegated) I thought was dead up until a couple weeks ago when it started shooting out new growth. Yes, I know they are a noxious weed now. Too bad because they are beautiful and butterflies and hummers love them. I planted them long before it was an issue. I make sure to dead head throughout the season and them cut them back hard in the winter.

My Adonis Blue still has no growth. :(

I lost all my butterfly bushes except one white one, and one yellow one is rather badly damaged. All the purple ones are dead. All the ones in 5-gallon pots are dead.

I have a six foot butterfly bush that I don't prune. this year the leaves at the very top came out and there are flowers on it. otherwise it looks dead. does anyone know what to do? my other two butterfly bushes died. if this is a weed, it is not a great weed.

If there are new shoots coming out of the bare branches and from the roots your plant should be find. If not, maybe the roots were killed from something, then your top growth will whither away. But if the top growth continues to grow and flower, then after they flower cut them back, better yet, cut it back after most hard freezes end for your area. In most of the PNW, that is late February. By spring you should have lots of sprouts with flower buds showing in June.

You are right, it isn't much of a weed in the PNW. I have been growing this plant since 1980 through many cold events that either killed them out right or severally damaged them. In Issaquah it got down to 12 degree F this last winter, which damaged the butterfly bushes I have left. The warm weather we have been having has helped them recover.

"You are right, it isn't much of a weed in the PNW."

LOL!! If you think that, come on over to th Kitsap peninsula and I can show you exactly how much of a weed this plant really is. Uncultivated, wild clumps of butterfly bush are everywhere. In very cold weather it can act like a herbaceous perennial, dying back to the roots but it springs back to life again with warmer spring weather.

The reason it is considered a weed and an invasive one at that each flower spike can produce as many as 40,000 seeds and those have an 80% germination viability. So just a single blossom left intact could produce 32,000 new butterfly bushes.

There are now butterfly bushes that are labeled sterile and say they will not spread. I am growing one and it has attracted butterflies, which I was worried about. The one I have seen are only 2 feet or so tall but very pretty.