Lifting and Overwinter Storage of White Pine in Southern Ontario

Abstract

A fall lifting and overwinter storage trial on 3+0 white pine (Pinus strobus L.) was carried out at St. Williams forest tree nursery (42° 40′N, 80° 25′W) during two consecutive years to study: (1) the degree hardening day (DHD) requirement for lifting; and (2) the effect of different storage temperature regimes: cold (1-4 °C) and frozen (−3 °C) on the performance of stock stored overwinter. Field performance was best if lifting for overwinter storage was delayed until after an accumulation of 125 DHD which is less than that required farther north. In some instances, seedlings lifted very late in the year had reduced survival and growth in the following year. Seedlings were ready for cold storage before being ready for frozen storage. Frozen storage is preferred owing to molding problems associated with cold storage.

Extension of the planting period of Norway spruce container seedlings: risks related to the drought – growth stage dynamics and handling practices

“…1996 One of the latest practices in nurseries at northern latitudes is to lift and pack seedlings in cardboard boxes in autumn and store them in frozen storage over winter, usually at −1 to −5 ºC (see Camm et al 1994 andMcKay 1997). The intent in frozen storage is to avoid risks related to outdoor storage, such as winter desiccation, extreme temperatures, feeding by rodents, growth of snow mould and also uneven bud burst and frost damage in spring (Baig and Tranquillini 1980, Racey et al 1985, Lindström and Nyström 1987, Colombo 1997, Grossnickle 2000, Paterson et al 2001. In addition, frozen storage allows greater flexibility in seedling delivery from nurseries in spring and also helps to ease spring workloads.…”