kim, can you whack back half-grown coreopsis to keep it from flopping?will poor soil help with the flopping?
I can't grow coreopsis because i don't have good enough drainage, but those are anti-flopping techniques I use for other plants.
best,
mindy

I planted 3 Coreopsis "Full Moon" from Garden Crossings in Spring 08. Fantastic plants: bloomed nonstop without deadheading at all. They are big and a bit lax: I put supports around the cluster of three after a heavy rain caused them to flop a bit. It is very different from Sweet Dreams: bigger and more substantial. This is the best coreopsis that I have every grown. I see from the Garden Crossing site that there is another new Coreopsis in this series ("Big Bang") for 2009. I'm going to give it a try.

Here's an interesting blog posting on new coreopsis varieties:

http://transatlanticplantsman.typepad.com/transatlantic_plantsman/2008/06/new-hardier-coreopsis.html

Here is a link that might be useful: Article on Coreopsis

Thanks for the link. What a nice range of colors on the new varieties. I will look for 'Full Moon' next month while on vacation in AZ. Then will test it for hardiness in z: 4 next winter.

Interesting article. I just read about Redshift on a couple of different sites. One listed it as zone 5, one as zone 4. I guess the next couple of years will tell. As for not being able to grow them because of drainage problems, try Zagreb. That is one tough plant. I have it growing in dry areas and damp, it seems to take whatever mother nature throws it's way.

I purchased C. 'Redshift' this summer, another Coreopsis in the "Big Bang" series. Definitely more upright and bloomed over a very long period, with butter yellow blooms sporting a red eye. I think it will overwinter here just fine, unlike C. 'Sweet Dreams', 'Heaven's Gate', 'Autumn Blush' and the others I've tried. It's gotten down to 20 degrees F here so far and 'Redshift' still has green basal foliage. So, I think this forbodes well for the other plants in this series.

All of the "Big Bang" series are excellent. They can survive cold temps, but need sharp drainage, becasue they can't stand "wet feet". My Full Moon blooms non- stop from June til really hard frost in October. Best Coreopsis I have ever grown, by far.

I have a whole row of Full Moon and they are wonderful (Central Ohio). But they do flop badly so a few weeks ago i trimmed them way back and they are growing back fine. Will have to see how well they flower. Last year, they flowered late, like August and then keep going til frost.
Does anyone have experience with Sunray Coreopsis?