Note for anyone in the UK or Europe: summer lilac (a type of butterfly bush) is highly invasive and spreads easily. In the UK consider planting native alternatives such as gorse which flower for most of the year. When gorse doesn’t flower, lavender will. For butterflies consider cow parsley.
Ceanothus and the mophead relative Hydrangea serrata can attract Butterflies in summer or spring, but Buddleja is still wonderful in this sense. The hunt for the elusive sterile Buddleja stills keeps going. Lots of promises in that sense with very complex hybrids, but they still didn't stuck with the market or didn't deserved the hype.
Gorse in a small garden can be complicated to manage. Too spiny and it reseeds itself. Rosmary or Leptospermum can take that job.
We've let the garden go wild this year (and last) because we're concentrating on other things. I can't help but notice how much the bees love the cow parsley that's sprung up, as well as the purple toadflax. Haven't seen butterflies on them unfortunately, they've declined to such an extent that now just seeing one is an occasion to point them out to my family.
If that were the case you would expect to see large growths of it in the wild, right? Whilst I do see it in the wild, I've never seen any situation where it looks to be taking over. I just see individual plants occasionally.
My reference for "highly invasive and spreads easily" is https://en.wikipedia.org/wiki/Impatiens_glandulifera#Invasiv..., which has by now completely taken over most clear and shady areas in and near forests where I live. Summer lilac is definitely far from being that bad.
> I've never seen any situation where it looks to be taking over. I just see individual plants occasionally.
Each one of those individual plants can produce 40.000 seeds each year, so give them a decade alone and you will see. Is very invasive on river beds and disturbed soils.
