Hi florabundance, Welcome to Garden Web and The Plant Exchange. You will likely get more offers to trade if you will either list in your post, or better yet, on your Member Trade List, at least some things you have available for trade. hth. Sue...chemocurl

Since there are few things that are as unattractive as shasta daisies after they have finished blooming, I cut them back down to their base as soon as the bloom cycle is over. They will typically regenerate a small amount of basal growth that remains in place over winter. But when you do this is up to you. You can back hard after they finish blooming (as I do), wait until you do your fall, getting ready for winter clean-up or leave them until you tidy the garden for spring.

Yes, you mentioned diviricata, already GG (I had just bought a calico aster) so I did indeed put one on order. I few years ago, I also managed to grow a really late aster - aster pilosum var pringlei (I think). Known as frost aster (by me) because it is SOOO late to bloom. Had forgotten about that one but it did survive the relatively dry woods so may also give that a go. I vaguely recall dealing with shasta daisies in a customers garden which didn't flower till Sepember. Am I thinking of a different chrysanthemum here (cos there are so many)?. Whites can be really tricky in an open sunny garden...but maybe with billowy grasses, late flowering umbels, achilleas and clouds of daisies, it might just work. It will certainly be very different to my usual late summer choices. I am also taking some silver-leaved cuttings (convolvulous cneorum, artemisias and caryopteris, to go with my silver leaved buddleja 'Silver Anniversary and various centaureas). I have all the 'bones' in hand - just needing fillers, so i is fairly thrilling. I am usually fed up by the end of July and have a month or so off until September, when my gardening mojo comes back. That is exactly what I do, a2zmom. I go straight from admiring the blooms to chopping the whole bunch back with no attempt to stay on top of minuscule floral heads, one at a time. Have a bidens just awaiting this exact treatment.

Depending on the specific cultivar, both echinacea and monarda will happy seed themselves. Some of the fancy hybrid echinaceas don't seed themselves. The regular purple coneflower echincea does. Their clumps will also increase over time. I've never seen shasta daisies seed themselves but the clumps will increase as well.