Can't answer #1 - never been to Cape May.

There are a few new, sterile (or mostly unviable seed) forms of Buddliea on the market now, however most of them are very dwarf, rarely exceeding 3-4' in size. Not very well-suited to training into a tree form :-) There is one that might work - 'Asian Moon' - which is supposed to reach 7'.

a picture will get you a lot closer to an ID ... did you take any on vacation???

in the alternative.. a sure stab in the dark .. call the county extension office in cape may.. and see if they can ID them for you .... just in case they are something other than a buddelia ...

ken

That is what I am attempting to do with my Butterfly bushes. I don't cut them down vertically but do remove lower branches and tidy them up. Yes, there is some pruning involved as they are strong growers. As far as invasive, I don't see any spread from seed and they have been in their current location for a few growing seasons so maybe they are sterile. Guessing they are about 7-8 feet now.

P.S., Cape May is zone 7b-8.

Both my Lo and Behold "Blue Chip" and Buzz "Velvet" say they are non-invasive on the tags. I believe Blue Chip said up to 4' and Velvet around 3'.

I have Bicolor, Black Knight and Royal Red as well as some Purple Emperors that overwintered here. Blue Chip and Velvet are new to me, but they both show hardy to either zone 5 or 6 (I think Velvet showed 6 and Blue Chip showed 5 but I can't recall for sure).

There are very few sterile forms of butterfly bush. 'Black Knight', 'Royal Red', Harlequin', 'Lochinch' - all of the standard Buddleia davidii cultivars are very fertile and can be extremely invasive in the right location and under proper conditions.

It has been determined that each flowerhead of B. davidii can produce upto 40,000 seeds with an 80% viability rate. These are dispersed by wind, rain and animal life and can spring up in rather remote places. One cannot make any assumptions about invasiveness just by monitoring how that plant performs in your garden. Check with your local invasive plant monitoring authority before determining what to plant.

Developing sterile forms of invasive plants is a big deal and occupying a lot of horticultural time and effort. Many of the plants that we consider to be great ornamental additions to the garden yet invasive in various areas - butterfly bush, Japanese barberry, nandina, burning bush - are the focus of these efforts. FWIW, this is not a new activity and some previous efforts at breeding so-called sterile cultivars have not panned out well :-)

Here is a link that might be useful: remote colonies of invasive butterfly bush

Kate, are you certain they were butterfly bushes and not Crape myrtles, which are in full glory these days?

Thank you all for your responses. The suggestion to call NJ County Extension was excellent. Will do so tomorrow when they open.

The more I read about butterfly bush, the less inclined I am to plant one. Invasive or not in my microclimate, the risk just seems too high.

And the more I read, the more I wonder if what I saw was not buddleia, but vitex agnus castus (I did not see the leaves close up). Any vitex experts out there?

Definitely not crape myrtle. They were all past their prime in Cape May, but just starting to come into their glory at my house.

Again, thank you all. Your time and information is greatly appreciated.

P.S. If you ever get the chance to visit Cape May, the gardens are plentiful and magnificent. It has a nice beach too ;-)

I love Cape May - we vacationed there when I was a child and I have great memories. Going to the beach in No California involves heavy blankets, a thermos of coffee and a rugged constitution, so the memories are all the more dear.

Regarding Vitex - the blue flowering varieties have absolutely stupendous color and impact. There is almost nothing like that deep, clear blue. However, they are very late to leaf out and are insignificant in autumn, so you have to be content with the summer drama and not expect anything more from it. If you place it properly (not close to a walkway or spot that you would see it up close during all seasons), it can work out very well.

Another caution - they are grown as both shrubs and standards; I have many of both. I would never buy another standard as that is not the plant's normal growth pattern and they get extremely top-heavy. They also sucker heavily and have awkward branching, which makes the standards rather tedious to maintain.

I would not bother with any color other than the deep blue (they come in white and pale pink) as you can find flowering shrubs/trees with much better habits that have those color flowers.

One person's opinion - gardening, as an applied science, is seldom absolute. See what you learn from County Ext and go from there!

CA Sara from NJ

Who monitors invasive species? I got some of mine (I don't know which they are, they were just "butterfly bush" with no cultivar or color named and none have gotten big enough to bloom yet) directly from my county's annual conservation district sale....

I just looked up Vitex...too bad zone 6 is "marginal" for them, they look interesting. I don't think I've ever seen one for sale locally, so I imagine "marginal" means "don't waste your money".

Isn't Vitex also also listed as an invasive?

I am zone 6 (northern NJ) and my Vitex, which I was told would die to the ground every year, is about 9 feet high, and close to that wide. It's not marginal here, even through the winter of '10-'11. As they say in the movies, zone recommendations are just a guideline.

Hm. I have read more on it now and have to say I don't think it's a "better" substitute for BB. I see it's listed in TX as invasive. It doesn't seem as common as BB yet, so I imagine that's just the start.

Yes, I too have learned that Vitex can be invasive. Ugh.

I've emailed the County Extension Service and the Nature Center, hoping that one of them might be able to help me identify the tree. May also try some nurseries and garden centers.

Too bad I didn't have the good sense to take photos or samples. Guess all that salt air just left me too relaxed to think.

Stay tuned...film at 11 :-)

Whimiscal,
There is a new and improved bush on the market, it is
beautiful and the fragrance alone is worth it.
It is also sterile.
I have one, I love it!
It is called Flutterbye bush.
Check it out online.

I ordered two Buddleia davidii 'Black Knight' plants that will arrive in May. I would think that dead heading the fading flower heads before they go to seed would not only promote more flowers but also prevent the plant from being invasive. I guess I'll find out for sure this summer. I never knew you could prune Buddleia davidii intom a tree: very interesting.

'Lochinch' is a hybrid and not pure B. davidii. But I have seen another selection presumed to be from different crossing of same species reseed. I would be wary of anything with B. davidii in it, whether it was pure B. davidii or not.

Deadheading will eliminate invasive potential on a site AS LONG AS IT IS KEPT UP. As soon as it is discontinued, if the specimen remains present beyond this point then it will be able to seed out anywhere there is suitable conditions. Here barren places such as margins of parking lots, river banks and even the stone faces of older buildings sprout numbers of them.

I didn't realize they were so invasive. Well, I'm only planting two of them, so it shouldn't be that hard to keep up...right?
I am planting them right next to some Miss Huff Lantanas. I also have Pink caprice Lantanas, Blanket Flowers, and Purple Cone Flowers within the vicinity, so all of that should keep the butterflies and hummers happy this summer.

This is what B davidii will do where it is happy. Picture taken November 2012 down the road from my place. As bboy said - it loves stony places including walls. The seeds are prolific and wind borne, so unless you can remove every spent flower before it ripens some will get away.

Wow! Someone needs to alert the building engineer of the problem. lol
I'm glad there are no stone walls anywhere in my area.

Worst infestations here are probably those around rivers, where it forms thickets. If there is no surface water it even grows in the river bed, as well as on gravel bars etc.

A river runs right through the middle of the town I live in. Due to the extended drought, it is more like a creek than a river, and there are shrubs and trees growing all over it now. I don't know if any of the shrubs are butterfly bushes though. The river is about a mile from where I live.
I do have quite a bit of barren ground in my backyard, which I am going to sprig it with Bermuda grass this summer. Hopefully, the Bermuda will help keep any Buddliea seeds from getting down into the soil if I lose the handle on deadheading them. If not, then I'm sure the lawnmower will make short work of them.

I wouldn't expect it to come up very often in grass or anywhere else a substantial growth of other plants was already present. Here it seems to be pretty consistent about appearing in bare places, often where there are rocks present to some degree. It's probably the same situation as with desert cacti, in that the young seedlings survive the harshness of the site by sheltering among rocks.

Those few places I have seen empress trees coming up from seed here were also always rocky - usually, in fact, stone walls or borders - except for a quite moist yet exposed patch of automatically irrigated flower bed across the street.

The summer drought here is quite an inhibitor for any plants not adapted to it or able to get into places where it is ameliorated enough for them get by until fall.

Well, it doesn't sound like I have much to be concerned about with Buddleia davidii popping up all over the neighborhood. I do enjoy dead heading, so I really don't think I will have an issue even if I were surrounded by rivers and stone walls. :-)

Here is also widespread along railway tracks, in disused sidings, etc. It loves the ballast, just as bboy says.

I have had butterfly bushes for 16 years here (central Alabama). In that time, I have had two come up from seed. I am not a reliable at dead-heading. I currently have 4 of them and love them. It is hot and humid here, and I have clay soil. that is mildly acidic.

The do not defoliate in the winter here.
kay

One of the things about Buddleja's invasiveness is that it does not necessarily self sow near the parent. The seeds are wind born and can travel miles before settling in a conducive spot. I have a lot coming up in my wood a long way from any gardens.

I do drive by one frequently that came up in grass, but it is beneath a chain link fence right on the edge of the lawn, in a rough strip where the mower doesn't reach. There are probably gaps in that part that made it possible for the shrub to take hold. The same section of fence also has broom (Cytisus scoparius) and I think blackberry (Rubus armeniacus) growing through it.

PLant native!!!....birds bees and butterflies came there for a reason in the beginning so perpetuate it! ( OK so maybe a couple of non native) And planting native can be hard..difficult to find plants..I've been trying and will keep trying.

Update: My Buddleia davidii has since been shovel pruned. I kept getting severe ifestations of Two Spotted Spider Mites. I tried to control them with a jet of water, but that didn't work. I tried to control them with foliar insecticide, but that didn't work either. The second year was more of the same, but the spider mites began to spread to other plants in my yard. That was when I shovel pruned the butterfly bushes. The spider mites are gone from my yard now and I'm still not sure why the Buddleia davidii in my yard had such a problem.

sam_md, so...when you're out deadheading your butterfly bush and you get hungry just pull off a Moon Pie or Twinkie and chow down?

It's my junkfood pic.