What We Do Here
The usual response I get when I explain the process of controlled pollinations is .. why go to all that trouble? Can't you just collect chestnuts off of a tree and plant them? The short answer is yes, you can, but because you don't know who the pollen parent is, you have no way of knowing what type of a seedling will arise from planting that nut. A nut planted when you don't know the pollen parent is termed an 'open-pollinated' cross. You might also see it listed as OP. For example, if I planted a nut from tree JAC-74 and did not know the pollen parent, it would be listed as JAC-74 x OP.
Controlled pollination would be comparable to selective breeding in cattle or horses. It is the process of attempting to improve the gene pool by breeding the best to the best. When trying to improve nut trees, there are a few steps that are necessary.
1) Isolate the female flower by placing a paper bag over it to protect it from stray pollen. With chestnut trees the bag is usually placed just before the pollen starts to shed, and remains in place until the flower is receptive. I have found that the peak time is about 10 - 14 days.
2) The pollen can be applied in a few different ways. If pollen is being shed at the correct time, you can simply drag an entire catkin over the flower. If the pollen is shed too early, it can be collected, dried and stored in the freezer until ready. This is my favorite method, and then I apply the pollen with a small brush. The bag is replaced after pollination. Some growers will remove the bag when there is no more pollen being shed, but rather than make any more trips up and down the ladder, I leave the bags in place throughout the season until it is time to harvest the nuts.
3) When the burrs first start to open, I collect all burrs inside the bags. Some of the nuts have fallen out of the burrs and into the bags, other burrs remain unopened. Those burrs that have not opened by themselves in a few days must be opened carefully so as not to damage the nuts. Some of the nuts are not yet brown, or fully ripe, but will finish ripening inside a ziplok bag with damp peatmoss.
4) The bags must be refrigerated for at least 3 months for the nuts to overcome dormancy. The nuts can be planted in containers, or directly sown into the ground in the Spring.
I have produced hundreds of trees by this method for almost 30 years.
Trees for Timber
The Mountaineer chestnut tree is the one selection that comes closest to resembling the timber qualities of the American chestnut tree. The American chestnut was renowned for it's high quality timber. It was straight grained, easily worked, and rot resistant. The US Forest Service estimated that the value of the American chestnut harvested in 1909 to be $20 million. That would be $500 million in todays dollars. In 1912 West Virginia estimated there was 10 billion board feet of standing chestnut timber. It was valued at $25 million ( $21/2 per thousand board feet). Today if you figured $170 per thousand board feet, those same 10 billion board feet would be worth $1.7 billion! I have also produced other American - Chinese and American - Japanese hybrids that are showing the potential to produce a high quality unique wood.
Trees for Wildlife
The American chestnut was a keystone species, which means many animals were dependent on it for survival. Most nut trees bloom early in the spring and are susceptible to late frosts. The American chestnut doesn't bloom until June - July and produced a good crop of chestnuts every season. The chestnuts were sometimes called the grain that grows on trees, due to the high carbohydrate content as opposed to the high protein and fat content of most nuts. The nuts are small, but very sweet with a good flavor. Some of the animals and birds that depended on the American chestnut were squirrels, chipmunks, black bears, deer, turkey, and grouse. The trees that I have produce nuts that range across the scale from large Chinese type nuts to small American sized chestnuts. Most of the wildlife seem to prefer the small sized chestnuts. I assume that is because they are easier to handle, but the black bears are fairly nondiscriminatory. They will eat anything in the orchard. Chestnut trees also provide shelter and nesting sites for several species of birds and animals.
Trees for the Environment
There are many ways in which trees are beneficial to the environment. Chestnut trees are one of the best lines of defense against climate change. According to the the folks at North Carolina State University, the average tree can absorb 48 lbs. of carbon dioxide per year. By the time a tree has reached 40 years of age, it can sequester 1 ton of carbon dioxide! American type chestnut hybrids will grow on the average 30% faster than oaks making them hard to beat when it comes to their ability to pull carbon dioxide from the atmosphere.
Female flower protected with paper bag and an aluminum tag to identify the pollen parent.
Pollen stored in a vial which will be applied with a small brush. This is my preferred method.
Male flowers, or catkins shedding pollen.