Container-grown seedlings are the most common stock types produced in B.C., however, field-grown stock types are still produced and planted to a limited degree. Most of the discussions in this guide refer to container-grown stock.
A stock type name is a shorthand method of specifying seedling morphology. For a given species, a stock type name is comprised of four elements -- container type/container size/seedling age/season of planting. In selecting a stock type, first consider the desired seedling attributes in relation to site conditions, and then specify the shorthand notation as illustrated in Figure 2.
Figure 2. Example of stock type nomenclature. Species is interior spruce, container type is a plug styroblock, container size is approximately 4 cm wide by 12 cm deep cavity with 77 cavities per block, age is one year, and the season of planting is spring.
|Table 1. Abbreviations and their definitions as used in container stock types|
|Container type||PSB plug styroblock
PCT plug copper treated
CRC container rooted cutting
PAP plug air-pruned (plastic block)
PAB plug air block (styroblock)
PPT plug-plug transplant
|Container size||Approximate dimensions of cavity (see Table 2)|
|Seedling age||Two-part code with the two parts separated by a plus sign; total equals seedling age. For example:
|Season of planting||Sp spring
|Table 2. Container stock type density, container dimensions, and soil volume|
Field-grown Stock Types
Bareroot seedlings are designated either BBR for seedlings seeded directly into nursery beds (Plate 1), or PBR for seedlings sown in a container in the greenhouse and later transplanted to the nursery bed (Plate 2). Stock age is also included in the stock type notation.