I'm thinking of planting a bunch of coreopsis between my sidewalk and fence, which is an unused part of my yard since I never go up that way, but i still want it to look nice. It's about a 30 square foot area. I want to just plant them and let them grow for years.

I was thinking about getting wildflower seeds of Coreopsis lanceolata. I assume that these would grow well and probably self seed (maybe). So, my first question is, do you think that would that work out ok as a good looking low maintenance perennial?

But then i found the Big Bang coreopsis, specifically the Cosmic Evolution coreopsis, which looks great. But, I'm afraid that it will die out after 2-3 years. Is that probably what would happen?

Coreopsis in any color other than yellow or yellow/orange usually only live a few years. I have I've tried to kill in years past and they keep coming back. I don't do anything to them and some are growing in some really heavy clay.

Well the climate here in Seattle is quite different than Cincinnati. But here is what works for me: 'Jethro Tull' Coreopsis. I have tried many varieties, this is the only one that is actually perennial here. The only problem with it is the dead flowers turn brown and hang on, and since it blooms from early summer until frost, that is a lot of dead flowers. There are two great ways to deal with this without deadheading daily. The first is to plant it where nobody sees it up close. Then the bright yellow flowers are what you see and the small brown deadheads are simply not seen. Done this way the only care it needs is cutting back once a year. Or just twice in the summer cut it back to about 8" tall, this takes a minute, within two weeks it is blooming again. For an unused area of the yard I think a plant like this would be great. 'Jethro Tull' is extremely drought tolerant. Mine is in hideous clay/builders rubble and severely neglected, but it does not seem to mind. I have never tried 'Evolution' so I can't say if it would be similar.

Coreopsis 'Jethro Tull':





Here is the same area in May, just before Jethro starts blooming. This is Geranium x magnificum and Geum 'Totally Tangerine', these are also extremely rugged and tolerant of neglect.

I find that most seem to last about 3 years, Route 66 is the only one that has gone longer for me.

I have found the threadleaf type is a long lasting one.
Moonbean is 6 years old here
Route 66 is 4 years
Sienna Sunset is 4 years
Mercury Rising 2 years
Center Stage ( a rose color ) has struggled for 3 years.I don't expect to see it this season.

I'm in zone 9b. Mine last about three years. Not long, but they self-sow and I'm always moving seedlings around where I want them to grow. I think they are so short-lived because they bloom themselves to their end.

@pepper23, does your coreopsis bloom in May when the iris bloom? or does it bloom later than that?

also wondering if these are eaten up by the japanese beetles?

Mine start blooming sometime in May and bloom all summer long. Never seen jap beetles eat them.

Mine don't seem to be blooming until June.

I bought two coreopsis Nana spring of 2016 and by fall it had spread to the point where I moved some to another part of my garden. It is still spreading like a ground cover.

If you want a tidy coreopsis, you might want to try coreopsis Nana. It's foliage is low growing, but it's blooms are fairly large and held at about 8" high. I have had several varieties of coreopsis and love the blossoms, but many of them seem to flop over and definitely look "wild". Nana is very tidy and spreads a bit. It has survived cold, heat, flood and drought. If I keep it deadheaded, it blooms from May till fall. I don't know if it would spread reliably from seed, but I have had it for several years and have spread it through divisions.