I'm not extra sure about it, and I have one out of three bushes which have survived the past three years. I think since these are borderline hardy in this area,that it's better to leave them and not prune until spring when you see what all has begun to grow. Most of the time they'll die down to the ground. I think it's a good idea to mulch very well over the roots..I heap a cone of soil about a foot deep over the crown of the root to protect it from the winter temps. I think the pruning is more done in Fall in warmer regions where the tops don't entirely die down.

Jeeze, I have a ton of stuff to put in the ground yet. I suppose that I'll bring most of it indoors to the sunporch and just overwinter them there. Then next spring when it's warmer out I can put them in the ground.. A butterfly bush is one of the things I'll be overwintering on the sunporch.... I need to quit buying stuff until I've planted what I have sitting around.

Diann
IA Z5a

Several years ago I purchased seed for the butterfly bush while in England. That winter, I started the seeds, and the following winter, I planted and over-wintered over 50 of the baby bushes! Talk about going a "bit" overboard! haha

Anyway, all the info I found said not to prune in the fall, but rather to do so in the early spring after growth had begun - and at about a foot height. Be patient in the spring, as they are slow to wake up from the winter. As the bush grows older, it won't completely die back, either, and the trunk will gain some size. They are a little "iffy" in our zone, so mulching sure doesn't hurt anything. I have lost very few, but given many away!

Diann, you aren't alone. I, too, have a bunch of things still not in the ground. I had to dig a lot of things out when we were having work done on the exterior of our home earlier this year. When I have things that don't get planted, I dig a big hole in the ground and sit the pots into it, and then cover it with leaves until spring (allow for about 2' of leaves on top of the pots). I have yet to lose anything. I'm probably going to have to do the same thing this year, as I just don't have the energy to take on the planting as vigorously as I usually do. Its nice to know you have friends, isn't it?!! Smiles.

Cora, I did basically what you did. Except, I used the Mantis to dig me a trench about a foot deep and I just healed in all the potted plants I didn't get planted this fall. Soon, I'll go rake up some leaves and pile them on top for winter protection. :)

Diann
IA Z5a

Diann...I just sent you an e-mail but now read about Cora digging a trench. So that brings up another question!

When you do the trench method, you only put leaves on top...no soil? And do you wait until the ground freezes before adding the leaves on top?

Cora, I'm wondering if you dig your hole so deep that you can still get two feet of leaves into it...so that the leaves aren't above ground level? That's a lot of digging!

Thank you!
By the way...I am 4b/4a, only in Wisconsin!

Hi, Mary and Diann-

When I said I "dig' a hole, I must admit that I use my trusted Mantis to do a lot of the work. I don't dig what I would call a "trench". It really is a big hole - this year about 5 foot square...just make it however big you need to get all the pots inside.

I DO dig it quite deep - usually 2.5 to 3' in depth and try to make sure the bottom is flat. Also, if you have a slight incline, that is nice, too, as it helps make sure nothing is sitting in water if the ground doesn't take the water quick enough - not a good idea to have things sitting with wet roots, so place the pots so the low end has fewer pots or raise the pots a bit in that area with rocks or something.

The perimeter of the hole is mounded with the dirt from the hole, so it provides an extra bit of protection from the wind. I put like-sized pots beside each other as closely as I can get them, and then shovel dirt in between the pots. (The first year I did this to discourage voles, mice, etc. from nesting in the hole over the winter, but I also feel it helps insulate the pots better.) Then, after all the pots are in place with dirt between them - as if they are just planted in the ground, but a few feet lower, I await the first hard frost. When that has hit, I then pile in dry leaves, along with large sticks and branches that may have falled from trees, so as to not compact the leaves too much. When the top of the hole is level (not the top of the sides of piled dirt), I place a few more branches over the top of the leaves, or anchor a tarp that will allow air flow, but not allow the leaves to blow away. One doesn't really need a tarp unless blowing leaves are a problem.

And, yes, the two feet is the space ABOVE the top of the pots. Its a lot of digging, but it provides the perfect place in the spring to amend dirt with peat moss, sand, and compost, before putting it into places in the garden, once the pots have been removed. When I finish doing that, I put the leaves back into the hole between layers of dirt and other compost. By the time summer comes around, I have a nice "bed" of good dirt to dig into if I need it, however since I got the Mantis Compost Twin, I haven't needed much additional mulch. That thing works great as long as I get the moisture balance right.

Hope this clarifies what I do. Now, if you don't have time to get those plants into the ground where you want them to stay, put them in a temporary location, settle them in for the winter, and enjoy planning next year's gardens!

A final "tip". Make sure all the pots have markers in them to identify the plant, AND, make a list of what is in the hole so you can plan over the winter as to where you want them to be placed. Its great if you can get them into the ground before they really start growing. Sometimes I put a bit of fertilizer on the top of the pots and allow it to work itself through the dirt over the winter. I think it makes the spring growth a bit...

Cora, Mary, nope, I didn't do as nice of a job as Cora did. I really did just dig a trench with the mantis about 1 ft. to 1.5ft deep and plopped in the pots. I then pushed the dirt in over and around them. They will be fine and next spring they will all find new homes in the gardens. :)

Diann
IA Z5a

do butterfly bushes reseed themselves? I thought I had only planted a couple but now I think I have 8-10 in my flower bed. They arent where I would put them so I think they are volunteers. Thank you!

Yes. Yes. And, Yes! They sure do! But they aren't always the exact color as the parent. I have several volunteers each year.

I have always been a bit leery of growing Buddleia davidii because of its potential for invasiveness. I know that the railroads in Great Britain consider it a scourge because it infests their track right-of-ways to the point of causing some derailments. I know that the climatic conditions are markedly different between Iowa and Great Britain and it may not become a problem here -- but I wonder.

Will, given enough time, it become a problem here as well? People said purple loosestrife (Lythrum salicaria) wasn't a "problem" here either until it became a REAL PROBLEM. I can still remember when the Hy-Vee stores were selling this as "Butterfly Bush" in spite of the plethora of warnings from other parts of the country that had become infested.

One only has to take a walk in urban Iowa woodlands to see the beginnings of problems with plants we believed would be "safe" to plant in Iowa. If you look closely, you can often find sprouted seedlings of Japanese barberry (Berberis thunbergii), Burning Bush (Euonymus alatus) and other problematic flora.

I was recently talking with our state forester and he related how there is growing concern about an unexpected infestation of Norway maples (Acer platanoides) in the Iowa City area. Small woodland areas are supporting hundreds of Norway maples per acre which crowd out, overwhelm and eventually kill all of the native flora. Citing a webpage from About.com:
"Why You Should Not Plant Norway Maple!:
The shallow, fibrous root system and dense shade of Norway maple make it virtually impossible for grass to grow under the tree. The aggressive roots frequently girdle their parent tree, ultimately choking itself to death. Norway maple is also a nonnative exotic. It has escaped the urban environment and is a threat to native maples."

I am trying to not sound alarmist. However, I long ago removed and destroyed any of the above mentioned plants that used to grow in my landscapes. When giving presentations I discourage their use. After conducting initial research of the Buddleia when it first started becoming popular in our garden centers, I took note of a potential for invasiveness. While no one can deny the beauty of this plant, I decided never to include it in my landscape. Will it eventually become a serious pest here? Perhaps not. However, there are thousands upon thousands of plants available with garden merit. If you can't get by without the few invasive and/or potentially invasive plants, you are not really trying.

If you can remember back, multiflora rose and Russian Olive were not a problem either until they also became a REAL PROBLEM.

IronBelly