1) Optimum container size depends on relationship between size of plant and how fast your soil drains. The faster the soil, the larger the container can be w/o concern for root issues. 2) The best mix would probably be 2/3 larger inorganic particles & 1/3 pine bark, but you could use a basic mix of pine bark, peat, perlite at 5:1:1to2 and expect good results. 3) Intervals between root-pruning will vary with your growing skill and container size. I'm guessing about every third year. 4) Regular pruning will be as required to keep the tree compact & in check size-wise. Best done before leaf-out or late summer while tree is developing and then, to keep it compact, in the first rest period after spring flush of leaves matures. No on the pollarding, but you will need to develop reasonable pruning skills to keep the tree looking good. 5) Chestnuts bear on wood that has acquired a particular ontogenetic age. Cutting back trees from seed would "reset" the age of the wood to a younger age (ontogenetically, not chronologically) and prevent flower/fruit. 6) Seedling/grafted - no matter. Get your "growing legs" under you any way you can. ;o) 7) Many chestnuts are susceptible to various disease & insect problems. Some are more resistant than others. This would be a good thing for you to research before deciding on a particular species, even genus, of tree. Al

Thought some of you might enjoy reading this! Rare chestnut tree still survives in Ohio State official let it slip that one mature tree stands in Ohio; its exact location is protected. Staff and Wire Reports Tuesday, March 25, 2008 SANDUSKY For about seven years, the state's natural resources leaders have harbored a secret. They still won't reveal the exact location of it or allow outsiders to see it. This Ohio treasure's existence was closely guarded until last week when the director of the Ohio Department of Natural Resources revealed that a full-size American Chestnut tree still stands in a marsh near Lake Erie, the Sandusky Register reported recently. For tree experts, it's a big deal. American chestnuts that grew up to 120 feet once accounted for about 25 percent of the forests in the eastern half of North America until a fungus wiped out all but a few. 'They are often referred to as the redwood of the East because of their tremendous size,' Gary Obermiller, a regional manager for the Division of Natural Areas and Preserves. The fungus was first detected in 1904 in trees in New York City, and by 1950 some 3.5 billion trees about 90 percent of the species were dead. Only a few trees had resistance to the fungus and survived. In Ohio, most American chestnut trees were found in the eastern half of the state. In August, the Dayton Daily News reported on the existence of a stand of American chestnuts anchored in a working sandstone quarry in Braceville Twp., Trumbull County, just west of Warren near the Mahoning River. The specimens that sit on a standstone knob are a handful, the tallest reaching 75 feet. According to the Register, the state's largest existing chestnut tree known only to a few until last week is in Sheldon Marsh, a 465-acre state nature preserve about midway between Toledo and Cleveland. The tree stands 89 feet tall and has a 5-foot circumference. 'To our knowledge, we don't have any that come close to this size,' Obermiller said. Most surviving chestnut trees are small, sprouting from the roots of trees killed by the fungus. Steve Maurer, the new chief of Natural Areas and Preserves, decided the public should be told about the tree, Obermiller said. 'He realized this was a very special tree,' Obermiller said. American Chestnut facts American chestnut trees once made up about 25 percent of forests in eastern North America. The trees grew up to 120 feet tall and lived up to 600 years. Its wood was valuable because it was straight, light and rot-resistant. A fungus that eventually wiped out most of the trees was first found in 1904 in New York. All American Chestnut trees in New York City were dead by 1912. By 1950 about 3.5 billion trees about 90 percent of the species were dead

ACF might be able to help you ID the species for sure, and they could maybe use the pollen http://www.acf.org/FAQ.php see question #6. Undeveloped nuts might be unfertilized - it takes two castanea trees to make babies! Are there other trees around?

YEah, look up "hypovirulence". Where are you located? If you're in an area with arid summers (i.e. the American WEst), you would have much more luck. The fungus has a lot of trouble producing it's tiny "mushrooms" (conidiophores) without heat AND humidity. I have seen 150 year old PURE AMERICAN chestnuts in Siskiyou County, Ca. that are thriving, where humidity is never more than 30% on 98 degree days. I have some seed from a naturalized grove that established itself on a clear cut near EUgene, Oregon I could send you, but it is most likely not pure American. I believe it might be EUropean/hybrid of some sort. Lawyer nursery sells seed of American Chestnut from a grove that survives in Michigan. Also, Cold STream Farm supposedly sells bare-root trees, they are located in Michigan. If you really are interested in American Chestnut, I would suggest reading Susan Freinkel's book "American Chestnut - The life, death and rebirth of a perfect tree". Amazing how the Forest Service helped knock this species closer to the edge of oblivion by declaring a policy of cutting ALL chestnut trees, living and dead. I believe that they figured any trees that weren't dead soon would be, so best to salvage the timber. They probably eradicated many trees that had some blight-resistant genes. Aside from working for the lumber companies and introducing exotic diseases (i.e. white pine blister rust) into the country, I guess they do SOME good once in a while...(?)