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.