(Revised 22 Nov 2017)
Coreopsis flowers are, profuse, bright and hard not to notice; even harder not to like in the summer garden. Some have dark green ferny airy leaves that are also highly ornamental even without the flowers.
Many of the new varieties are not reliably hardy to my area, but I like them enough to try them out anyway. It appears the best survival strategy is to plant them in the drier part of my garden and not adjacent to other plants that need more regular watering. The dry condition may minimize the floppiness of some varieties. Some varieties are a little weedy spreading under all their neighbours.
Coreopsis ‘Autumn Blush’
It survived only one season. It is similar to ‘Redshift’ but inferior in terms of survival reliability.
Coreopsis ‘Baby Sun’
It survive one season before destroyed by voles. The bright orange yellow can be useful in some compositions. There are a number of varieties with similar looks.
Coreopsis ‘Cosmic Evolution’
It survived one season. Compare to ‘Star Cluster’, it is slightly more cream and seems weaker. It probably deserves one more try.
Coreopsis ‘Cosmic Eye’
It survived first winter but not particularly vigorous.
Despite coming in as a little weak plant, it survived and bloomed a couple of seasons before it was killed by over crowding of adjacent plants.
Coreopsis ‘Full Moon Improved’
This is one of the best Coreopsis in my garden; beautiful cream colour, long season bloom, vigorous and reliable.
Coreopsis ‘Heven’s Gate’
It is quite showy even though it is kind of pink. It survived one season; probably worth one more try.
Coreopsis ‘Mercury Rising’
This is probably the most showy Coreopsis in my garden. It is vigorous and long blooming. It appears that the survival rate may depend on how much energy do you want your plant to spend blooming its head off into winter.
Coreopsis ‘Red Satin’
This is a little more reddish than ‘Mercury Rising’, just as profuse bloomer.
This is the best cream with dark eyes Corespsis I have. It is reliable and vigorous.
Coreopsis ‘Star Cluster’
It survives well in our winter, and is probably the best white I have.
Coreopsis ‘Tequila Sunrise’
It survived a few winters before eaten by voles.
This is an annoying weed. Its flower is OK, but it likes to send runners underneath all of its neighbour. After putting up with it for a few years, I decided to remove it from my garden.
I have this for years. I don’t particularly like the yellow flowers, but the ferny refreshing green foliage is worth having it around.
Coreopsis verticillata ‘Route 66’
This is a vigorous and reliable Coreopsis with tons of showy flowers. It is also long blooming. The yellowish orange brown colour makes it hard to use in composition.
Coreopsis verticillata ‘Sienna Sunset’
I sowed them from seeds. So far it seems weak but manages to survive the winters well. The interesting shade of peach colour has a place in my garden.
Coreopsis verticilla ‘Zagreb’
This is a boring yellow variety.