Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact. Most winter raspberries are flown in from the southern hemisphere. Quality is often poor because raspberries have an extremely short postharvest life and bruise easily during shipping. In the northeastern United States, many greenhouses are empty during the winter. In addition, by holding dormant raspberry plants in cold storage during the winter and bringing them into the greenhouse at staggered intervals, they can be made to ripen for several months before and up to the normal raspberry season, dramatically extending the season of availability.
Raspberries appear to be uniquely suited to winter greenhouse production.
However, commercial enterprises are only now beginning to develop. Raspberry flowers require pollination to set fruit, so a successful greenhouse production system must ensure adequate pollination. Bumble bee hives are now commercially available, and bumble bees appear to be superior pollinators to honey bees in the greenhouse. In addition, biological control agents have been developed recently to manage greenhouse pests, making pesticide sprays unnecessary and allowing the bumble bee pollinators to thrive. In addition, with deregulation of electric power, costs for heating and lighting should decrease while the cost of fuel for transportation is likely to rise.