by U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station in Portland, Or .
Written in English
|Statement||by Carl M. Berntsen.|
|Series||Research note -- no. 165., Research notes (Pacific Northwest Forest and Range Experiment Station (Portland, Or.)) -- no. 165.|
|Contributions||Pacific Northwest Forest and Range Experiment Station (Portland, Or.)|
|The Physical Object|
|Pagination||4 p. ;|
Diagnosis table — Douglas-fir, oak and pine Note: These tables list commonly encountered signs and symptoms and likely causes, but not every possible symptom or potential cause is noted. Douglas-fir diagnosis table. Trees help keep a forest fertile. Forestry Research West Fort A test planting of and Douglas-fir trees on a steep south slope. Res. Note Portland, OR: U.S. Department of Agriculture, Forest Service, Douglas-fir stem growth per unit of leaf area increased by inter- planted Sitka alder and red alder. Forest Science. 30(1 Cited by: 2. Planting a Douglas Fir Tree. Before you start growing Douglas firs, you’ll need to find a good planting location. They grow best in areas with cold winters and hot summers in U.S. Department of Agriculture plant hardiness zones 4 through 6. When you are planting a Douglas fir, be sure to site the tree in an area with excellent drainage. The Douglas fir has been used as a Christmas tree in the Pacific Northwest since the s, because it was one of the most commonly found in the area. Douglas firs grown for Christmas trees take years to grow to the right size depending on the growing conditions, the trees are sheared once every summer so they grow in uniformly in shape.
Attempts to grow Douglas-fir as a Christmas tree outside its native range have failed, due to frost and needle cast diseases. Coastal Douglas-fir will not tolerate frost below 14 degrees Fahrenheit for more than a week, even if the ground is well protected against freezing by snow cover. Damaging Agents. Douglas-fir beetles prefer weakened or recently downed trees. You can reduce the damage by keeping tree vigor strong and Douglas-fir blowdown to less than four inch diameter (or larger) Douglas-fir trees per acre. The Douglas-fir beetle is most often found following extensive blowdown of mature trees. This is a pretty difficult situation for a plant as the roots of the big Douglas fir will take all of the moisture and nutrients out of the ground. Where I used to work (at the Miller Garden), we planted under large conifers, but we added about 2 centimetres (5 in.) of mulch each February, which built the soil up. In addition, we watered regularly. How to Transplant a Fir Tree. A fir tree is a type of evergreen conifer with several varieties that can be transplanted in U.S. Department of Agriculture hardiness zones 3 through 8. The best time.
The cones of the Douglas fir are distinct, /2 to 4 inches long. Protruding from beneath the thin rounded scales is a conspicuous, three-pointed bract. On older trees the reddish brown bark is broken into oblong, longitudinal plates and may be 10 to 12 inches thick. Two varieties of Douglas fir grow in the Northwest:* Pseudotsuga menziesii var. menziesii grows in western Oregon and Washington from sea level up to feet ( meters). Pseudotsuga menziesii var. glauca grows between and feet in the northeast corners of Oregon and Washington, and the mountains of Idaho. Growing Grass Under Douglas Fir Trees - Knowledgebase Question. Pests and Problems. Turner, OR. Question by lorab2 If you are determined to grow lawn there, the first thing to do is perform some basic soil tests to determine if the soil is in good enough shape to support a lawn or if you need to add any amendments. Your County Extension. The Rocky Mountain Douglas-fir grows best in soils in areas with gravely, acidic soils. Coastal Douglas-fir grow faster and larger of the two varieties (the Coastal Douglas-fir and the Rocky Mountain Douglas-fir). They grow up to feet and the old-growth forests can reach .