In 1991, USDA Forest Service geneticists and resource specialists from PNW Research Station, several National Forests, and Dorena Tree Improvement Center met to discuss the potential of using containerized seed orchards (CSO's) for western larch to meet the need for seed in eastern Oregon and eastern Washington. It was decided to establish two small prototype larch CSO's at Dorena TIC and to develop the technology based on research elsewhere with various conifer species.
In 1992, scion wood from parent trees from two National Forests was collected and used to graft onto larch rootstock to become the start of the larch prototype CSO. In addition, larch seed from parent trees on the Colville National Forest was sown to establish a small prototype seedling CSO. In succeeding years, additional grafting was done to lay the foundations for anticipated operational production of larch seed.
Progress to-date shows that western larch can be grown in relatively small containers, and the plants remain vigorous. Production of seed and pollen cones varies by year and by parent tree, but seems to be relatively light so far. Pollen from parent trees from the forests has been used to supplement the pollen available thus far from the orchards. The percentage of filled seed per cone has been relatively low.
[Larch Orchard Photo Gallery]