In 1840 , Henry Wadsworth Longfellow immortalized the American chestnut with the dustup , “ Under the spread out chestnut tree the settlement smithy stands … ” Now , just shrubby , shortsighted - lived sprout remain of the American chestnuts ( Castanea dentata ) that once dominated the eastern half of the United States . The only American chestnut seedlings that pull round today have been crossbred with Taiwanese chestnuts ( Castanea mollissima ) for blight resistor .
American Chestnut History
At their peak , more than 3 billion American chestnut tree trees towered over 200 million acres of hardwood wood inUSDA plant hardiness zones 5 through 8 . They boom from Maine to the Florida Panhandle and from southeasterly Massachusetts to south fundamental Mississippi . Their directly - grained , decline - resistant wood supplied America ’s settlers with :
Wildlife junket on their sweet , vegetable oil - rich nuts , as did the settler and their livestock . Countless tons of the nut were roasted at the year - end holidays . The tempestuous trees — which often stood more than 100 metrical foot tall and 12 or more feet around — survived up to 300 years .
The Blight
In the late 19th 100 , Chinese chestnuts carry chestnut tree barque blight ( Cryphonectria parasitica ) were import to New York . By 1950 , the airborne fungus had nearly wiped out the Tree east of the Mississippi River . Only their root system survive , sending up sprout that rarely live more than 10 yr .
American Chestnut Seedlings
An effort to reestablish American chestnut tree seedling has been on-going since the 1980s . In 2015 , the American Chestnut Foundation planted several hundred seedling that ensue from backcrossing American and Chinese chestnuts .
The crossbreed have the blight electrical resistance of their Chinese ancestors . Everything else – about 15/16ths of their DNA – is from their American one . They’regrowingon U.S. Forest Service land in North Carolina , Tennessee and Virginia .
Expert nurseryman ’s hint : backcross meant breed the first genesis American / Formosan chestnut cross back to its American parent and double through six generation until only one Formosan trait – blight resistance – remained .
Can You Plant Backcrossed American Chestnut Seedlings?
Sixth - generation backcrossed American chestnut tree seedling will be evaluated in the natural state for several more age . It may take decades to prove their blight resistance . presently , the best blight - resistant seedling available to home gardeners is ‘ Dunstan , ’ a 2d - generation backcross .
Growing ‘Dunstan’ Chestnuts
Although hardy in USDA zona 5 through 9 , ‘ Dunstan ’ chestnuts need at least 250 hours of winter temp between 33 ° and 45 F ° ( 0.55 ° to 7.2 ° C ) to produce nut . To ascertain pollination , embed the seedlings in pairs or groups . Growthem in full sun and well run out , sandy loam dirt with an acidic or neutral pH.
