Buddleia are rampant growers better known for the requirement of hard pruning than for fertilizer needs. I have never considered fertilizing this plant that threatens taking over the garden. Al

I'm glad someone did a topic on this plant. I've fertilized mine once so far, with liquid Miracle Grow.

I do know they need to be deadheaded.

Calistoga, I bought a small plant last summer and kept it in a pot. I put it in the ground in the Fall like the directions said.

It really didn't grow last year and bloomed just a tiny bit, I was kind of disappointed.

But now it's about a foot and a half tall and bushy. Will this plant really grow to 4-5 feet this summer? If so, I can't wait!

It just sat there in the Spring not doing much but now it's really taking off. I wonder if it's because of the Miracle Grow?

You are in different zones.

Growing them will be very different.

Up here in 5B they die back to the ground in the fall and only reach 2-3 feet for me.

I have used MG once a week on mine and they produce beautiful flowers!

Keriann~

I am in the same camp as Al. Good Lordy no, I don't put anything on them. They top out at five feet easily and need to be held in check. I am in the zone five/six cusp and they do die back each year, but come back with a vengeance.

I know they aren't exotics, but they volunteer so easily that I have to rip out new ones in spring. Agressive is almost accurate.

I have never fertilize my butterfly bushes. They're doing well without it so why fertilize? They apparently don't need fertilizer or good soil because they're not getting either here. I just cut back to about 12 inches in late March and deadhead when needed. They are already 5-6 ft.

Unfortunately, buddleja is an invasive alien in the UK which overtakes disturbed ground, especially gravel, rubble, derelict buildings etc. It colonises whole stretches of railway land and is spread by seeds. I have seen it growing way up in the air straight out of the mortar in an old wall. It often starts growing out of badly pointed roofs and chimney stacks. So it is very happy in harsh conditions and has absolutely no need of fertiliser! The attached link is quite a long article but I thought it was very informative and some of you might be interested.

Here is a link that might be useful: Buddleja information

I have 2 large Butterfly bushes and don't fertilize them either in zone 5b, but do top dress them occasionally with compost and they are mulched with leaves that fall in the garden. A little bloom fertilizer might help but obviously isn't necessary.

Mine get about 6 feet tall and I cut them down in April when they are showing healthy green shoots. They are doing fabulously well this Spring, because our winter was a bit on the mild side. Usually I deadhead regularly to encourage more blooms, but one summer I couldn't because of an injury. They have never produced a single seedling either way.

Buddleia davidii is an interesting example of how a plant can be terribly invasive in certain climates, and not invasive at all near the limit of its cold tolerance.

Thanks for the info. I've just bought one for my AUD Zone 4 setting (around Zone 10-11 USDA). I won't fertilise and see how I go. I know they're invasive in more southern areas of aus, but given my climate, mine might not be interested in growing here at all. I did find one website saying they grow to zone 11, so we'l see...(always fun to experiment!)