This Hibiscus is on my Bucket List but I will never be able to grow it to seed harvest in Nutley NJ. I may have a two winter old, North American native Hibiscus aculeatus, also in section Furcaria, which just may set seeds for the first time, if I can avoid a killer frost for the next two weeks. And yes, it also has a chromosome count of 72. The trick to growing Hibiscus aculeatus in Zone 6b may be keeping it roots wet all summer.
[quote="locoluna"]Would you like me to root you cuttings?[/quote]
As much as I would love a specimen of Hibiscus radiatus, in my Zone it would be a house plant for half the year. What you could do is collect seeds from your Hibiscus radiatus and grow them. I would be very interested to learn if there are any variations in the onset of blooming dates. Locating a Hibiscus radiatus which blooms in September would be a major step forward. Now that you know what Hibiscus radiatus looks like, be on the lookout for anyone else growing this species and note the dates when their Hibiscus blooms, the earlier the better. I would also be interested in how long it takes for seed pods to develop and seed yields. Photographs are always welcome.
Attached is a photograph of a flower from my one surviving North American native Hibiscus aculeatus taken on September 3, 2012. Not show is the fact that the Hibiscus is in a 10” grower’s pot standing in about 4” of water in a cement mixing tub with other water-loving Hibiscus. Hibiscus aculeatus can be found growing in roadside ditches throughout the American South. This Hibiscus has made it through two winters and I hope to harvest seeds in a few weeks. Actually three plants made it through the winter of 2010-2011 but because of construction about the house, I lost two. I will be ordering more seeds, from a different grower, to start in the early spring of 2013. This should give me two different genetic sources to breed for cold tolerance and earlier bloom times in this short-day Hibiscus.
If I even obtain a self-sustaining line of Hibiscus aculeatus in Zone 6, I will then become very interested in Hibiscus radiatus & Hibiscus acetosella. Pollen storage may also be a necessity as Hibiscus aculeatus will be blooming early. If anyone with Hibiscus radiatus or Hibiscus acetosella is interested in growing a more cold tolerant line of Hibiscus aculeatus from seeds in Florida with the potential to hybridize with other Hibiscus, please send me a DM.