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Abies (grandis)

Kasten Dumroese
Research Plant Physiologist
USDA Forest Service, Southern Research Station
1221 S. Main St.
Moscow, Idaho 83843
(208) 883-2324

Family Scientific Name: Pinaceae
Family Common Name: Pine Family
Scientific Name: Abies grandis (Douglas ex. D. Don.) Lindley
Common Name: Grand fir
Species Code: ABIGRA
Ecotype: Northern Idaho
General Distribution: Grand fir is found throughout British Columbia to California and west toIdaho and Montana. It occurs most frequently on deep, moist alluvial soils in gulches, along streams, and on gentle mountain slopes.
Propagation Goal: plants
Propagation Method: seed
ProductType: Container (plug)
Stock Type: 66 ml (4 cu. in) Ray Leach "Cone-tainers"
Time To Grow: 9 Months
Target Specifications: Height = 15 cm Root-collar diameter = 2.3 to 2.8 mm Firm root plug
Propagule Collection: Single or small bunches of erect female cones occur in upper portions of the crown on the upper side of young branches. Dense clusters of smaller male cones occur lower on the crown on the underside of 1-year-old twigs. Ovulate cones are deep purple-brown, 5 to 10 cm long. Each cone contains numerous, angular, tan seeds that are 6 to 7 mm long with a broad wing 1 cm in length. Cones require 2 years to mature. Cones mature from mid-August at lower elevations to September and early October at higher elevations. Trees begin bearing cones at 20 years and produce a good seed crop every 2 to 4 years. Seed cones shatter at maturity.
Propagule Processing: Ovulate cones should be collected only when fully mature, but before they disintegrate and disperse seeds. Cones can be collected by climbing older trees and hand picking cones, but this can be hazardous because fir branches tend to be brittle and tops may break off. Pole pruners can be used for cutting cones from medium-sized trees, or cones can be collected from recently felled trees. Fir seeds are fragile and can be easily damaged during collection and processing. Cones can be put into burlap sacks and must be kept cool and shaded during transport and storage before processing. During storage, burlap sacks of cones must be inspected and turned at least once per week to facilitate even curing and drying.
Once cured, disintegrated cones can be tumbled or passed over vibrating screens to separate seeds from cone scales, Use caution when de-winging fir seeds. Seeds must be separated from sharp debris before they are de-winged. Screening is less damaging than using a de-winger to remove wings.
Seeds/kg = 36,000 to 63,400 (16,500 to 28,800 seeds/lb).
Seeds dried to 9 to 12% moisture content can remain viable for 10+ years when stored at temperatures from -18 to -5øC (0 to 23øF).
Pre-Planting Treatments: Seeds are placed into fine mesh bags and soaked in running tap water for 48 hours to ensure imbibition.
Mesh bags are placed into plastic bags and seeds are stratified (cold, moist) for 14 to 42 days at 1 to 2øC (34 to 36øF). After stratification, seeds are soaked 24 hours in running tap water.
Based on cumulative germination at 21 days in a germination test, the total amount of seeds needed for the crop is determined to ensure 90% to 95% of the cells have at least one seedling.
Growing Area Preparation/
Annual Practices for Perennial Crops:
Seedlings are grown in 2 fully-controlled greenhouses. Photoperiod is extended by 300 watt incandescent lamps (15 min on/off cycles) at an intensity of 500 lux. Irrigation is applied by an overhead traveling boom system, with nozzles spaced every 40 cm. Fertilizers are injected into irrigation water with a 1:100 injector.
Containers are filled with a 1:1 (v:v) Sphagnum peat moss and vermiculite medium having a pH of 4.2.
Seeds are sown in late March and are immediately covered with a shallow layer of white grit or Forestry sand (6 mm deep) and immediately irrigated (acidified to a pH around 6.0) until the medium is saturated. Using a medium with low pH, irrigating with acidified water, using grit to allow air circulation around the root collar, keeping relative humidity low, and using underbench air circulation and heating reduces damping-off disease. Day-time greenhouse temperatures are maintained at 24 to 27øC (75 to 80øF), and night-time temperatures aremaintained at 18øC (65øF).
Establishment Phase: Once seedcoats begin to fall off germinating seedlings, seedlings are thinned to 1 seedling per container. Germination is usually complete within 14 to 21 days and seedcoats are shed within 28 days.
Photoperiod lights remain activated. Nutrients are supplied about twice a week. During the establishment phase, seedlings are fertilized with Peters Professional Conifer Starter (7N:40P2O5:17K2O; The Scotts Company, Marysville, Ohio) and CAN-17 (liquid ammonium calcium nitrate [17N]) to supply 84 and 46 ppm N, respectively, along with micronutrients (Fe, B, MgSO4). Phosphoric acid is used to keep pH of irrigation water around 6.0. Seedlings are irrigated when blocks weigh 80% to 85% of saturated weight. At the end of week 8, medium is leached with irrigation water to remove salt build-up. Day greenhouse temperatures are maintained at 24 to 27øC (75 to 80øF) and night temperatures around 18øC (65øF).
Length of Establishment Phase: 8 weeks
Active Growth Phase: During the active growth phase, day-time greenhouse temperatures are maintained at 21 to 24øC (70 to 75øF) and night temperatures are maintained at 18øC (65øF). Photoperiod control is continued.
Nutrients are supplied about twice a week using Peters Professional Conifer Grower (20N:7P2O5:19K2O; The Scotts Company, Marysville, Ohio) and calcium nitrate (15.5:0:0:10) to supply 120 and 46 ppm N, respectively, along with micros (Fe, B, MgSO4). Containers are irrigated when blocks weigh 80% to 85% of saturated weight, but this is slowly decreased so that by the time growers wish to initiate buds, containers are irrigated at about 70% saturated weight. Seedling heights are compared to those on a target growth curve, and if growth exceeds targets, nitrogen is reduced by decreasing the amount of calcium nitrate to 23 ppm N. Conversely, if growth is lagging, calcium nitrate can be applied at 69 ppm N.
Seedlings generally reach desired heights by week 12, and medium isleached with copious amounts of irrigation water. Medium is then allowed to dry down until it is just barely moist.
Length of Active Growth Phase: 5 weeks
Hardening Phase: When irrigation is necessary, Peters Professional Conifer Finisher (4N:25P2O5:35K2O; The Scotts Company, Marysville, Ohio) is applied at the rate of 24 ppm N every other irrigation. Calcium nitrate is applied at the rate of 24 ppm N every other irrigation. Micronutrients (Fe, B, MgSO4) and phosphoric acid are supplied every irrigation. Photoperiodic lighting is discontinued. Day-time greenhouse temperatures are maintained at 18 to 21øC (65 to 70øF), and night-time temperatures are maintained at 17 to 20øC (62 to 68øF). Beginning in mid-October, we allow air temperatures within the greenhouse to reach ambient levels. However, minimum greenhouse temperature allowed is -2øC (28øF). Seedlings are ready to be packed in January. From mid-September until pack-out, day temperatures are kept cool as possible and we prevent night temperatures from dropping below -2øC (28øF). Seedlings are hardened for 18 to 22 weeks.
Length of Hardening Phase: 18 weeks
Harvesting, Storage and Shipping: Seedlings are extracted for storage in late November through December. Seedlings are well-watered before removal but foliage should be dry before packing.

Seedlings are placed within plastic bags inside waxed boxes or plastic tubs and stored at 0.5øC (33 to 34øF). Seedlings are monitored for storage mold problems. Storage molds can be reduced by packing disease-free stock, storing them for the shortest possible duration, inspecting the crop for on-set of mold, shipping seedlings with minor mold occurrence first, and keeping temperatures below freezing.
Length of Storage: 4 to 5 months
Other Comments: Between crops, containers should be sterilized. We submerge Ray Leach "Cone-tainers" in hot water (75 to 85øC [167 to 185øF]) for 15 to 30 seconds to remove pathogens.
This protocol was originally developed in the mid-1980s when David L. Wenny was Director of the nursery and published as Idaho Forest, Wildlife and Range Experiment Station Bulletin 45.
References: Dumroese RK, James RL, Wenny DL. 2002. Hot water and copper coatings in reused containers decrease inoculum of Fusarium and Cylindrocarpon and increase Douglas-fir seedling growth. HortScience 37:943-947.
Wenny DL, Dumroese RK. 1987. A growing regime for containerized western larch seedlings. Moscow (ID): University of Idaho, Idaho Forest, Wildlife and Range Experiment Station. Bulletin 45. 8 p.


Dumroese, Kasten. 2009. Propagation protocol for production of Container (plug) Abies grandis (Douglas ex. D. Don.) Lindley plants 66 ml (4 cu. in) Ray Leach "Cone-tainers"; USDA Forest Service, Southern Research Station Moscow, Idaho. In: Native Plant Network. URL: http://NativePlantNetwork.org (accessed 2021/07/27). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.

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