Controlled-release fertilizers, applied to the root zone of 1-0 plug Douglas-fir (Pseudotsugamenziesii Mirb. Franco) seedlings at planting, stimulated shoot and root growth in the following two growing seasons. Stem unit length was increased in the first growth flush after treatment, and a higher proportion of fertilized seedlings had a second growth flush that year. Fertilizing increased the number of needle primordia formed in the overwintered bud in the late summer and fall of the 1st year after treatment and increased the number of lateral buds formed the following spring, but did not affect the length of stem units elongated in the first growth flush of the 2nd year after treatment. Shoot–root ratio was not altered abnormally by fertilizing. Fertilizing increased the number and in some cases the diameter of lateral roots in the root system. Position of fertilizer placement did not alter root system symmetry in terms of the distribution of numbers of roots over 12 root zones.

A method is presented for rapid determination of the mitotic index in terminal buds of Douglas-fir, Pseudotsugamenziesii (Mirb.) Franco. Fertilization at planting increased mitotic index but fertilized seedlings entered dormancy at the same time as unfertilized seedlings. Cold storage, prior to dormancy, reduced mitotic index rapidly and was related to reduced height growth the following year. The effects of moderate moisture stress and seed source on mitotic index were slight.

Root systems of 5- to 8-year-old Pseudotsugamenziesii (Mirb.) Franco seedlings of natural, bareroot, and container origin were quantitatively analyzed to determine the effects of seedling source on root system morphology. Lateral root orientation was stressed.Container and planting constrictions on root system morphology were recognizable after outplanting; planted stock types were differentiated from seeded-in-place seedlings on the basis of root system morphology. Container and natural seedlings had less variation in root system morphology within stock type than bareroot stock. Root spiraling was so low in the Douglas-fir stock types studies that it is not likely to affect tree stability. There was no overall effect of root system morphology on height of seedlings around 6 years of age.

Root systems of Piceasitchensis (Bong.) Carr. seedlings of natural, bareroot, and container origin were quantitatively analyzed to determine effects of seedling source on root system morphology, particularly lateral root orientation.Planted stock types were differentiated from natural seedlings on the basis of root system morphology. Container-induced effects on root system morphology were no greater than effects of bareroot cultural and planting practices. The data presented indicate that effects of culturing and planting on root system morphology are probably not severe enough to cause instability or growth retardation.