Rouge, which types of Coreopsis didn't overwinter for you? I was just thinking about buying one after seeing the pics on the other thread.

Of those I remember: "Cosmic Eye" (the hardiest for me), "Early Sunrise", "Cosmic Evolution", "Presto", "Star Cluster",.....

I was looking at pots of 'Mercury Rising' (dark red) yesterday and wondering if it would survive. Does anyone in zone 5 have feedback on this one?

One of the ones with colors that vary with the temperature, perhaps 'Red Shift' hasn't outright died in the last three years, but it always takes a long time to come back and doesn't look like much until well into July. I can never be sure about plants in this bed, however, if their issues are vole related or lack of hardiness since it's the bed that has the worst vole issues.

I have done fine with some of the older thread-leafed varieties like rosea, Zagreb and Moonbeam. I also have found that 'Golden Gain' a taller, larger flowered thread-leaf has done well for 3 growing seasons, so I think it is a keeper. And of course the older C. lanceolata types do well here also.

'Jethro Tull' (Georgia developed hybrid) is the only Coreopsis I've bought over the last few years. Seems to be doing fine here.

Picture (June 17, 2015): planted several years ago.

Wasn't the Cosmic series introduced by Daryll Probst and supposed to do better in zone 5 than the previous generation of disasters (whose name I forget but many people lost them in a season)

I thought "Ill believe when other people see it"

Interesting that idea of cutting off flower production in September. Can't be any worse than them

not showing up again in May.

Mercury Rising and Star Cluster have returned successfully for me in zone 5 Ontario for the last two (brutal) winters. Just impulsively purchased Heaven's Gate which I'm finding out now might not be as lucky. I'll be sure to follow the tip given above to better its chances.