Stewartia ovata seeds are not that easy to grow. They require 3 to 5 months of warm/variable-temperature stratification followed by around 3 months of cold stratification. If I was going to try it, I'd soak them for about 24 hours. Start off with a glass of hot tapwater. Dump seeds in and cover to retain temperature for at least a little while. Then, I'd plant them outside under a light layer of mulch and mark their location. I'd protect them from predation and leave them. Water during dry times. If they do sprout, it would probably be the next spring.

If I really wanted one of these, I'd just buy one instead of growing from seed. There are too many easy-to-grow-from-seed plants to be messing with a rascal like this one. If you were growing them from seed in hopes of getting a special plant or trying to propagate a large batch, that would be different.

Thanks for the info Brandon - I'll give it a try - I'm on a much more limited budget these days so was just going to give them a try to see what I might get.

Frances

I would get them in the ground or seed tray and see what happens.
Have they been stored in a warm, heated house? Not good. They need some cold stratification.
I don't know if this has any correlation or not, but I get volunteers seedlings from a couple of Stewartia monadelphas I have. They come up in aged wood chips under, and around, the parent trees. No volunteers yet from my S. pseudocamellias.

botann - thanks for your input - I have an area that I think I can mimick "the wood chips under tree" where you have volunteers. It is a protected area and the mulch and compost are very aged - I use it to sometimes start cuttings so maybe that will work - plus it's an area I can mark and dedicate to these seed. Maybe I'll get lucky!!!

Frances

I think planting them outside will give them their best shot, but, for anyone trying to grow these, don't just give them "some cold stratification", because that's not all they require. The initial warm stratification (moist storage) is just as important as the cold stratification.

I have successfully germinated 3 ovata (yes, only 3) so far but it took the following..... warm stratification in moist vermiculite 5 months followed by cold stratification for 5 months. Then I planted 3/4 inch deep into pots filled with 50/50 peat moss and potting soil and allowed them to sit out a full year, including a freeze cycle over winter. I never let the soil dry out. This spring, 3 came up so far, hoping for more, but I expect them to germinate sporadically over the next couple years. Hope they survive and are worth it!

Other stewartias have taken just as long or longer using the same methods but if you stick with it, one spring day your pots will erupt with seedlings as my pseudocamelia and koreana have done this year from 2006 seed sources.

I know that this is an answer to the above question quite a few years after the asking. Stewartia ovata and Stewartia malecodendron are the two wonderful native American species in the genus Stewartia. We grow both species.... How they got in our American south eastern woods is a question for paleobotanists to answer. Probably a remnant population from when the continents were connected many of 100 of millions of years ago, when the Asian continent was connected to North American continent...that far back! These two species are all that is left of perhaps quite a few other species of Stewartia that may have developed during the ensuing million of years. We will never know how many species and perhaps even genus of plants were killed off by the persistent burning of eastern forests by early native Americans, the eruption of the volcanic caldera at Yellowstone , which covered forest land all over central America with large amounts of ash ( we are due for a big eruption,one is coming soon!!!!!) and by later European land clearing over the last 400 years or so. . We will never know..... Imagine the plants that were lost....The oriental species are far more easy to germinate than these two American natives. Stewartias native to the U.S. are much like the only two peony species native to North America, P. brownii and P. californica. These two species of peony are the eastern most members of the genus. These rare native herbaceous peonies arrived here in North America around 50 million years ago through the Bering land bridge, perhaps carried by animals , or perhaps by birds. These two native species of Stewartia and the two native species of peony both require special warm cold treatments, a protracted warm period, followed by a lengthy cold period. Again, we grow both of them..... a challenge, to say the least.

Asian Stewartia's also need a lenghty period of warm-cold stratification. Are American Stewartia species so much different?

The American species of Stewartia are much, much harder to grow from seed. All of the species of Stewartia are a challenge to root. They will root. It's getting them to break dormancy once they have rooted in the next year..Frustrating for many. That's the problem. Grafting is an option for the truly skilled plantsman. Surviving rooting has to do, maybe, with the tissue not lignifying, turning woody, hardening off properly...Cut the stem of an Asian Stewartia and you can see the chlorophyll throughout the stem. Not like a lot of other hardwoods where the chlorophyll is located , for the most part, in the cambium layer just below the bark layer. . .The Asian species are easy to germinate. The American species are very difficult. From personal experience they have proven to be a challenge.

One species that has eluded quite a few is Stewartia rubiginosa. A lone herbarium specimen can be found at Harvard...It's flower , so I have been told, is the largest of all of the Stewartias. It is, apparently, four inches plus across and looks much like the other Asiatic species. An exhaustive search for it over a five year period, for the seed, proved fruitless.Perhaps others might have more luck. It's name appeared on propagation sheets from Chinese state run nurseries that were acquired from back in the 1990s, along with a host of other never heard of species of quite a few other plant groups.Imagine a flower in the six inch range, one that would hold for more than a day. The purple foliage varieties have cropped up in seedling batches throughout the years. Cooler temps seem to influence the intensity of the foliage coloration.Interesting plant....

Hi Mr Alpine Distributors...............I used to grow pseudocamellia in a small downtown lot. I have now moved to where I can grow virtually all of the trees I lusted for over the years when I lived on a small city lot. Since I loved my pseudo, one of the groups I am working on is the Stewartias. I have pseudo, a small tree & all of the others I can get I either have as planted seeds or am still looking out for. Never heard of rubiginosa before so I am interested to hear more. Perhaps you could contact me off list.....let me know if you are interested & I'll post my e-mail for you.

Check out THIS relevant post on the Native Plants forum.

I have 2022 seed for both S. stewartia & S. malacodendron and have supplied Sheffield's in the past. alarkaexpeditions.com

This says the petals of S. rubiginosa are 2.5-4 cm. So the width of the flowers is 5-8 cm plus whatever the base adds.

Stewartia rubiginosa in Flora of China @ efloras.org

Meanwhile there are selected named forms of S. pseudocamellia that produce 9-10 cm flowers. Since this is the best species overall for decorative plantings anyway those would be what to try and get. When the biggest possible flowers are the goal.

Stewartia pseudocamellia - Trees and Shrubs Online