Growers of the strawberry now unite mainly in the belief that the flowers of the pistillate varieties are capable of enduring unharmed frosts and adverse weather conditions that destroy the germs of perfect varieties. The reason given is that pollen-bearing is an exhausting process. As the pistillate sorts bear no pollen they are able to store more perfectly the cell-structure with the needed nutriment to resist frost and exposure.

This storing up of plant-food is important in orchard fruit-culture. The variety of the orchard fruits and small fruits that ripens its wood perfectly in autumn will best protect its fruit-buds in winter and its flowers in spring, and will best endure frosts and trying weather conditions. In top-working and ringing this same principle applies. These operations favor the more perfect ripening of all parts of the top, and experience has demonstrated that given varieties top-worked or ringed will bear fruit when the blossoms of root-grafted trees are ruined by frost. The altitude, air-drainage, and porosity of soil and subsoil also have much to do with the ripening of all parts of the tree, including the flowers.