Chinese Ash Seeds

 Immune to the Ash Borer=Vigorous Tree with Dense Wood  

Starting in the early 90's I began growing many types of ash species. At the time, my mini-ash collection was a mixture of species done specifically for finding new species specifically for wood production and street trees. I began growing many diifferent species found in Europe and China.  At that time the nursery industry was primarily growing native ash trees all of which were highly susceptible to ash borer.  When the ash borer did hit Michigan, I suddenly had renewed interest and purpose in my trees. Keep in mind the ash borer started in Michigan so the ground zero effect plus having mature ash trees on my farm helped in understanding the imapact of this tiny insect.  By the time my Chinese ash trees were large enough for the borer to infect absolutely nothing happened. A line of native ash trees less than two hundred feet away from my planting all came down with the insect. My trees were untouched. Eureka!! 

The name rhychophylla refers to the leaves with are oblong and come to a point.  The origin of this seed source came from a wild collection given to me from a research scientist friend of the farm in its earliest days.  Since then, no ash borer has been able to penetrate the bark or infest the Chinese ash tree. How can rynchophylla do it? It is likely related to the high amounts of tannins found within the sap of the tree which is a natural insect repellent. Only once did we find one hole drilled partially in where the insect attempted entry without success. 

Now over 35 years old, the trees have been flowering and setting seed.  Red squirrels consume the seeds in great numbers at my farm. The trees have naturally seeded nearby on the edge too.  The seeds remain dormant for two winters before sprouting in the spring. One tree appears to be seedless so far. This might be a good selection for reproducing by grafting for a shade tree. Many ash tree selections are seedless to begin with. It stops the spread of the tree with cost of not feeding the wildlife. 

Chinese ash is an easy tree to establish. It grows a variety of soils reaching up to 40-60 ft. tall in average soils. The broad spreading trees will have some of the same characteristics that people like about ash trees including symmetrical branching, straight growth habit and uniform crown. 

This plant is not frost prone. The flowers are fragrant.  The wood is incredibly dense. Even with the best loppers, it was quite an effort. This would be a good species to establish and get the ash tree back into production again especially for use in urban areas. Selections could be made for low or no seed production and then easily grafted like other cultivars are produced. 

To germinate the seeds: Simply plant 1/4 inch deep and lightly cover soil with compost or peat. Seeds need a double dormancy to sprout. That means fall plant and then go through two winters. Seeds will sprout quickly the second spring. You can replicate the first winter dormancy by storing the seeds in damp peat and storing in the fridge as your first winter dormancy. Once in a while a few seeds will sprout during the first season. 

Currently harvesting with a good crop. 2025-26 years