Coreopsis x ‘Jethro Tull’
Coreopsis auriculata ‘Zamfir’
Coreopsis lanceolata ‘Early Sunrise’
Coreopsis ‘Jethro Tull’ is a hybrid cross between Coreopsis auriculata L. var. ‘Zamfir’ (female parent) and Coreopsis lanceolata L. var. ‘Early Sunrise’ (male parent). This cultivar was introduced by Itsaul Plants in 2008 (PP18789).
Both parent species are correct and accepted scientific species names of the genus Coreopsis. Both were named and described by Carl von Linnaeus in Species Plantarum in 1753.
I am not sure how many species there are in the Coreopsis genus. The Plants of the World Online website by Kew only lists ONE accepted species of Coreopsis and six species that are now synonyms of other genera. They are new and still uploading data, so we’ll give them a break. The new site is going to be really great! The 2013 version of The Plant List named 100 accepted species (plus 3 accepted infraspecific names), 183 synonyms and 51 unresolved names. The Plant List is no longer maintained.
A good friend and fellow plant collector, Walley Morse, gave me this clump of Coreopsis ‘Jethro Tull’ in the spring of 2012. It did very well so I brought it with me when I moved back to the family farm in mid-Missouri in February 2013.
I dug a new flower bed on the south side of my parents home and put it in the west side of the bed. I didn’t like it in that spot, so I moved it to the east side.
Coreopsis species are very variable and classifying them is complicated to explain. They are very closely related to the genus Bidens. Several Coreopsis species have been moved to other genera including Bidens. The Wikipedia gives great information provided by GRIN (Germplasm Resources Information Network-USDA) which divides the species into 11 sections… GEEZ! Coreopsis is a very variable species.
Origin: Hybrid from North American species
Zones: USDA Zones 4a-9b (-30-25° F)
Size: 18” tall and wide
Light: Full sun
Soil: Average, well-drained soil
Water: Average water needs. Drought tolerant once established
Propagation: Divide clumps in spring every 2-3 years
Maintenance: Deadhead spent flowers for repeat bloom.
Concerns: Mine died from mildew. Can crown rot if the soil is too moist for too long.
Coreopsis are very good garden plants and a number of species and cultivars are available from many sources. One of my favorite sources would be Bluestone Perennials. Coreopsis ‘Jethro Tull’ are proven hardy in USDA zones 4a-9b, but many species are hardy down to zone 3.
The Coreopsis ‘Jethro Tull’ started out fine in the spring and flowered well all summer. Toward the end, though, it started having an issue with powdery mildew. I a not sure if it returned in the spring of 2014 or not but I don’t have photos past 2013. I really liked this Tickseed and there are several cultivars on my wish list. Since I had the issue with powdery mildew, I am not so sure now…
I hope you found this page useful. If you have any comments, questions or suggestions, I would like to hear from you.