Preparing Seedlings for Planting

Early Spring Planting (no acclimatization)

Handle seedlings as little as possible during the early spring when they will probably be exposed to freezing nighttime temperatures. During this time of year, daytime temperatures are commonly below 70 degrees Fahrenheit for extended periods and warm temperatures are reached for only a few hours in the afternoons. Soil temperatures do not warm in these conditions.

Completely thawed seedlings should be taken from boxes and prepared for wrapping if wrapping is prescribed. Seedlings should be dipped briefly in water or misted and then wrapped in moist tree-wrapping fabric or clean burlap (see wrapping for more details). If roots are sufficiently moist, dipping may not be necessary. Wrapped seedlings should be kept cool and planted within 48 hours after wrapping. If seedlings are wrapped before planting, place them back in cold storage (32 to 36 degrees Fahrenheit) immediately with the tops of the bundles up and exposed to air.

An alternate method is to remove seedlings from storage boxes at the planting site, dip small bundles of seedlings briefly in water, and place bundles immediately in insulated planting bags. Make sure that all roots are wet. Do not allow planters to carry too many seedlings. Seedlings kept in bags for long periods will dry out. Vary the number of seedlings in a bag based on the temperature and humidity conditions on the site.

It is critical to keep seedlings, especially pines, from becoming active physiologically and transporting a lot of water to the stem and tree crown. Seedlings that are full of water may be damaged after they are planted when temperatures drop below 28 degrees Fahrenheit. Early season mortality in ponderosa and lodgepole pine can be partially attributed to freeze damage from planting seedlings with excess water in stems and needles just before temperatures drop into the mid-20s or colder.