Question
Hi Tom:
Ive asked you a question here once about transplanting hydrangeas.  New questions for ya.

Im in Zone 6 on the southern coast of Massachusetts.

I have a nice summer garden that gets thick and green and flowers from June to late Aug. After that, it all dies back.  (Might tenor phlox did notthing this year cuz of a cold may.  Its usually up and at em by mid Aug.)

I want to get some perennials in there that will start to bloom when my other plants start to wilt.  So Im looking for somethign that will start growing in late Aug, bloom in Sept and stay alive for most of Oct.  Is there such a thing?

The garden has great soil; I take care of it every year..just composted it today actually.  

However, Im concerned with overplanting, too.  Dont know if I need to be concerned about that if I threw in another five varieties of plants in there for the fall.

Ive got two red astilbes, one large hosta, penstemons, monte negro lillies, one large day lilly (red), purple tall tenor phlox, cambridge monardas (bee balm) and purple salvia


Answer
Hi Ken,
Thanx for your question.  Perennials such as chysanthemums and asters would be perfect for this, also Stonecrop and other varieties of Sedum (mine are beginning to bloom now).  Hardy Hibiscus is blooming now and will continue to bloom until frost.  I hope this helps.
Tom