"What we are trying to research is a production system that would allow us to produce selected clones or cultivars that can be used in our local industry. These production systems could be used by local growers to produce the trees here instead of relying on nurseries on the West Coast," said Rupp, who received his bachelor and master's degrees at USU and a doctorate from Cornell in New York.

With this in mind, he said the folks at USU are looking at improving three characteristics of the tree: color, disease resistance and form.

To that end, Rupp has collected tree samples that show more intense and longer lasting colors from different mountain areas and at the old botanical gardens at Farmington.

"Our next factor was disease resistance. Most native maples are susceptible to leaf spot disease and some other diseases. If you can grow a tree that is not going to get diseases so you don't need to spray, that gives you a better tree," Rupp said.

Form is also important. Rupp said Bigtooth maples tend to grow as a multiple-stem tree. He and his colleagues would like to cultivate a tree that has a strong central leader that would produce the type of landscape tree most people want. "If we can find more oval or more columnar tree forms, that would be even better," he said.

Trying to grow the plants from seed presents several problems. Bigtooth maples usually flowers every two to three years, so the seed supply is not reliable. More importantly for a nursery production system, plants that grow from seeds are extremely variable, so the color, size and disease susceptibility are out of the growers' control.

Rupp hopes to solve this problem with a technique used to propagate fruit-tree rootstocks and other ornamental plants. These techniques bypass the seeds, giving exact duplicates of the parent plants.

"Maple trees often propagate in nature through layering," Rupp said. "We can take trees that show the characteristics that we want and then grow them in a stool or mound layering bed to get more of the trees we want."

To do that, the plant is cut back to about an inch above the soil during the dormant season. The dormant buds produce new shoots in the spring. Soil is then mounded over the new shoots, which will develop new roots. The plant can then be harvested the next season.

"We could still bud or graft these trees onto seedling rootstocks, but that is a more expensive way of producing plants and takes more time. Collecting and storing the wood takes much more labor and is another step we would like to eliminate," he said.

Currently, there is only one bigtooth maple cultivar on the market — Rocky Mountain Glow — and it has several problems. The most serious is that it is grafted onto a standard sugar maple rootstock, which increases its susceptibility to iron chlorosis. It also shows a poor branch structure and its fall color is nonexistent.

Rupp is confident that his work will yield better trees. "We are always looking for even better forms of this great tree. When we find them and then offer a way to produce them economically here locally, everyone is a winner."

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Larry Sagers is the horticulture specialist for Utah State University Extension at Thanksgiving Point.