Differences Between Southern and Northern/Western Conifer Seedlings

In the South, the nursery is usually at the same elevation and in the same climatic zone as the area where the seedlings will be planted. This greatly simplifies matching the physiological condition of the seedlings at the nursery with the conditions needed for successful planting. It also means that the seasons for lifting and planting are identical, except in the late winter when the nursery should have completed lifting, but the planting season continues for stock stored cold.

Southern species tend to develop less dormancy than those from the North and West. They are never stored frozen. Cold storage durations are also much shorter. Under ideal packaging and storage conditions, southern conifers can be kept in cold storage for up to 8 weeks. Optimum storage conditions—33 to 38 °F at 95 percent or higher relative humidity—are the same as with the northern and western conifer seedlings.

Seedlings are lifted at the nursery and shipped as needed with little cold storage at the nursery. A typical southern nursery may have a production capacity of 25 million seedlings but only be able to store 1 to 2 million seedlings in cold storage. The nursery cooler may be used primarily to bring the stock temperature down to 33 to 38 °F so seedlings can be shipped and stored cold at the district. This would take just a few days, so turnover in the nursery cooler is rapid.