I can tell you that for "perennial sunflowers", the combination of
these Helianthus maximiliani and Heliopsis is great. The Heliopsis are
shorter at about 4ft and bloom viciously for me from late June to
mid-August with a few flowers even beyond that. They are not really
"sunflowers" but I think they are sometimes called oxeye.

As stated, these Helianthus run about 6-8ft, start in early Sept and
go until frost. Both perennials are very easy to grow from seed and I
attach a photo of the shorter Heliopsis from July 3 of this year.

JD





Want some!

Mary