I recently read an article that said not to grow this plant because it's so destructive to the environment. It claimed the root system would drill through foundations and garden walls. It also claimed the plant is poisonous to insects, especially butterflies. I know they can be invasive some places due to self-seeding. The article said the root system runs riot through the soil. What is true?

Yes, butterfly bushes can be invasive in some areas. Mostly due to seed (over 30,000 seeds on one plant is often claimed) distribution. Their roots can regrow even if the main plant is removed as can stems left. I have not read that the roots destroy foundations, etc, but common sense suggests that any large shrub planted too close to foundations/sidewalks/walls/etc, can do root damage.

I have never heard that they are toxic to insects. The closest I've heard is that in North America there are no butterflies that lay eggs on, or that caterpillars eat the leaves of, the butterfly bush. So if they are allowed to propogate in natural settings and take over from native plants, they basically prevent butterflies from successfully breeding and growing to maturity.

There are sterile non-invasive variations.

I would base your decision to grow them on local education sources rather than general articles. Your nearby university can be a good source for advice.

I know that UC Davis routinely sells a few variations at their sales - recommending them for pollinators (insects and birds).

I currently have 8 Buddleais in my back yard.
They are not poisonous to insects in my experience. In fact, butterflies, bees and hummingbirds love them.
I am in zone 6 here and if it gets too cold here over the winter, they can die back to ground level. It was -7F here last winter so two died back but sprouted this year from the root system.
They flower from July through September and bloom better if you dead head them. I have pinks, purples and a very dark purple. One seeded in all on its own. None of mine are near a foundation. However, lots of plants can be bad for a foundation if planted too close.
Butterflies that like it here include Painted ladies, Black swallowtails, Tiger swallowtail, Giant swallowtail, several species of skippers, Red admiral, and Monarchs.
As toedtoes mentioned, they are prolific seed producers. BUT I dead head the flowers faithfully and probably reduce seed production by 90%! I dead head not to cut back on seeds but to promote more flowers.
Honeybees and a few bumblebee species visit them too.

labellaflora said: I recently read an article that said not to grow this plant because it's so destructive to the environment.

I think that most of us have read this... And many of us agree.

As far as poisonous?
I have to agree with Toedtoes that these plants don't actually harm the pollinators who visit, but there are far better plants to grow for them.

I like the vitex, it has similar flowers, and is capable of supporting caterpillars to feed the birds and the birds love the seeds!

At my house, I don't get seedlings, the birds seem to get all the seeds...

Also... I don't know what the climate is like at your house, but butterfly bushes don't tolerate droughts, mostly require very moist soil... Entirely too much valuable water is required to keep them from dying in a dry location.

At my house, I have blooms on the vitex now, in spite of how dry it is...

I just googled your climate... Very dry... You probably shouldn't even try to grow this wetland shrub unless you want to put in a liner and create a bog garden...

There are some varieties that are drought tolerant once established and/or have low to moderate water needs. You just have to check each variety before buying.

But, you still aren't adding to the diversity of the yard as well as my suggestion...


Manduca rustica caterpillar on vitex...

Imagine the feast for the nestling baby birds!

Having that caterpillar in my yard producing a moth may be just fine for some, but not me.

I am primed to add some favorites of butterflies this coming summer. Plants like fennel, Butterfly weed and Common milkweed. I have removed an old dog house from the previous owner and I now have room for 3 additional large planters.

It all depends on what the OP is wanting for their yard.

Milkweed is toxic to cats and dogs, so it's a concern for some folks.

Butterfly bushes don't get bigger than about 8 feet, and there are the pugster varieties that are even smaller and make good container plants. Depending on the variety, vitex can grow from 4 to 35 feet so they may not be practical for some yards.

Everyone's needs and preferences are different. If the OP is specifically looking for plants that will support the life cycle of butterflies, then passing over butterfly bushes is a prudent choice.

But, if the OP just wants a colorful plant that is not toxic to their pets and will provide nectar for pollinators and hummingbirds, then there are sterile drought tolerant butterfly bushes that fit the bill.

I grow, and can recommend, the following "dwarf" buddleia; all are sterile:
B. davidii 'Buzz Magenta'
B. davidii 'Buzz Ivory'
B. davidii 'Buzz Candy Pink'
B. davidii 'Buzz Indigo'
B. davidii 'Buzz Sky Blue'
B. davidii 'Buzz Velvet'
B. 'Blue Chip'
B. 'White Chip'
B. 'Lilac Chip'
B. Flutterby Petite Dark Pink
B. Flutterby Petite Blue Heaven
B. Flutterby Petite Snow White
B. Flutterby Petite Tutti Fruitti
B. Flutterby Flow Lavender

Although they are called dwarf, they can grow medium-tall if not pruned. I don't give them much care other than pruning and deadheading, and they are very attractive, colorful additions to the garden, always full of hummingbirds, bees, and butterflies. I have trained two small plants into 4-ft-tall standards.

Many years ago I mistakenly planted the large, fertile, buddleia, and have since taken them out, as they do grow like weeds, although mine did not spread. If not constantly pruned and deadheaded, they can be unattractive.

Catpaworchids said: Having that caterpillar in my yard producing a moth may be just fine for some, but not me.

I'm trying to figger out what you have against night flyin' pollinators...

Those sphinx moths are simply spectacular...

I have nothing against night flying pollinators in total.
I love my bats that fly around my house at night. Just some spectacular fliers, acrobats really. I had 7 bats flying around one evening in early August. I can't imagine how many mosquitos they are eating.
I love Luna moths. Stunningly beautiful!!
Cercropia moths are another cool moth.
I just don't care particularly for Sphinx moths, and I really do not know why. Well, one is responsible for my tomato hornworms but I only have seen a couple here over the last 6 years.
My favorite African orchid, Angraecum sesquipedale, is pollinated by a night flying Sphinx! But why don't I care for them, I honestly don't know. Call it a phobia, call it misguided dislike or even a hatred, but I have never really appreciated them.
It might even be a "3 horse race" between them, Starlings and Rock doves!

Those warnings about the root system of buddleia seem exaggerated. My experience has been, it is a short lived shrub, prone to splitting near the base after several years, introducing rot.. In my zone, I pruned down to a foot or two tall every winter.

Oh yes sally, great point. I do prune mine back heavily, maybe 2/3. I get fuller bushes that way and I assume that the flower count is better if you prune.

Yeah, my year old ones are really scrappy looking. I need to go out today and prune them back - thanks for the reminder.

If you prune them hard now, they will look that way until next spring. You can just deadhead them and maybe thin out some weak stems. They will look 'fresh' without just sitting there looking 'chopped' for 4 months.

They are REALLY scraggly - look like scarecrows. I haven't pruned them before. Thinning them hard now will improve their appearance over the winter.


Oops. Cancel that. Will wait to trim. They are getting a few new blooms and there was a butterfly on one just now. So pruning will have to wait.

Isn't that just the way? You've been told.

I like plants that tell me what they want. Nothing worse than an uncommunicative or passive aggressive plant...

Hi there folks,
Here in zone 4, well maybe 4b, I can't grow Vitex, although I would love to. I can grow Butterfly Bush, and mulch them heavily over the winter.
If I prune them back in fall here, for some reason they do not survive. They do best when pruned back in spring after seeing the first green sprouts. I did have a 15 year old magnificent Black Knight that the Monarchs loved. It did not survive a long cold wet spring - and ended up with root rot.
I too deadhead regularly to keep the blooms going as long as possible - our fall can become too cold too early. Frost finishes the blooming period, and I take off the dead blooms that are remaining.
The Hummingbirds also love Butterfly Bushes, and we are on their migration path, so the nourishment on the way is helpful for them.
Even my long lived bushes have never done any harm to the foundation. Their roots are pretty fragile.
In our zone, these are probably not dangerous or prolific spreaders. In other areas, where they survive the temperatures more easily, perhaps they are more of a problem. I do understand wanting to be careful not to take over areas where more helpful native species need space. But in this zone, they are more of a help for pollinators than a danger (I believe).