I grew 'Black Knight' Buddleia from seed via winter sowing back in 2009 and the next year planted out dozens of seedlings that have since grown to maturity. I have them in multiple garden beds, planted in both full and part sun. They're healthy and appear to be bothered by few pests. Flowering is abundant and the butterflies & other pollinators are on them constantly once they bloom. So far none of mine have topped 10 ft. tall which may be related more to sun exposure and soil type than anything else. Butterfly bush should be pruned back to 10" in spring each year (March where I am) since it blooms on new wood. Other than that it's completely maintenance-free. You don't post your location or zone so be advised Buddleia is listed as invasive in some states due to its prolific reseeding.

Keith, I agree that you should tell the nursery they sold you the wrong buddleia. Perhaps they will give you Black Knight since b. weyeriana isn't what you wanted. But I hope you keep b.w. and post back on how it grows for you. I have b. davidii royal red which has a different charm, so I understand why you want black knight. My b.w. is honeycomb which has custard yellow flowers. I saw it locally on a garden tour and instantly knew I wanted it. Here in NM it grows to about 6' high, around 4' across. Unlike b. davidii it is more upright and statuesque. It makes a BIG statement! The garden where I saw it had a semi-circular bed of them, about 6, all in bloom. It took my breath away. I spoke to the owners about hardiness. They said they had had them for about 8 years. We're supposed to be Z7, but we've had subzero winters twice in the past 4 years. The b.w. had a lot of dieback, but they pruned it and it grew back strongly. Good luck, Cheryl

Your problem right now is possibly due to lack of deep watering and a hungry soil. You're absolutely right to pick up the dead leaves because that does help to cut back on reinfection. For the soil, if you can add a good thick mulch of well-rotted garden compost (so you can't tell what went into it) and some ancient, no-smell-now steer or horse manure which is all crumbly, mixed in. About one bucket of manure to four buckets of compost. When autumn comes put about a two gallon swish of wood ashes around each plant. That's ash from untreated wood only. The ashes add potash and that helps strengthen the plants against disease and frost damage, too. You'll probably find that you'll get black spot again toward the end of the summer when all manner of fungi start showing. Just use one of the recipes already supplied. And, for next year - start with a well-fed soil. You can repeat the compost application in spring once growth has begun - but keep it back from the stems. The compost you put on now - and in the autumn - will be what the roses will be calling on for goodness to grow with. The spring application won't really become available until further on in the season. If your plants are getting too dry, you may also have a scale infestation along the stems. You can reduce this with winter oil or even soapy water and a dishwashing brush scrubbed over the infested stems. Prickly work - but worth it.

Eww, that's nasty. I had an infestion not quite as bad on some euonymus last year, but I got rid of it. Don't give up. Scale can be controlled. Timing is the key. You can spray all you want at the wrong time, and it won't do any good. You have to get scale insects in their 'crawler' stage, which is a narrow window of a week or less. Check with any good local nursery or a county extension agent in your area to find out when they'll be vulnerable. You may be too late for this season (ours were crawling about , but you can get them over winter, too. Use a dormant oil spray like Ortho's Volck Oil, which is available everywhere. Forget about the cooking oil and dish soap concoctions. They're too unpredictable and may hurt the plant. Spray the diluted Volck Oil at the recommended intervals during the dormant season and then watch for scale carefully next season. If you need to spray plants during the growing season, follow the directions for diluting the Volck Oil to growing-season strength, which is half as concentrated as the dormant season spray. Tina McG