2 questions:Autumn Joy sedum grows well for me but by Sept. the flower heads...

Asked September 28, 2016, 12:11 PM EDT

2 questions:
Autumn Joy sedum grows well for me but by Sept. the flower heads are heavy, bend or break in spite of grow rings. any ideas?
I like Rudbeckia but are there varieties that don't get the black spots? I'm not successful in getting rid of them.
Judy Kipka

Hennepin County Minnesota rudbeckia septoria leaf spot sedum

1 Response

Autum Joy gets pretty floppy. Some people like to cut them back once they are about 6-8" tall. Remove about half of the height. This will keep them a little shorter and hopefully more upright, but will also delay blooming by a few weeks. Other gardeners feel that dividing their sedum every year or two helps, as does keeping them in a very sunny, dry area. Rich, moist soil encourages lush growth that cannot hold itself up. Still others replace their Autum Joy with newer cultivars that don't flop.

Rudbeckia's septoria leaf spot can be hard to control (http://www.extension.umn.edu/garden/yard-garden/flowers/diseases-of-rudbeckia/ and https://ag.purdue.edu/btny/ppdl/Pages/POTW_old/9-30-13.html). 'Goldstrum' is the most common kind of rudbeckia and it is very susceptible. ‘Becky’, ‘Cherokee Sunset’, ‘Irish Eyes’ and ‘Prairie Sun’ are more resistant.