376 MINNESOTA STATE HORTICULTURAL SOCIETY. 



twigs of the new growth, through which evaporation would take 

 place. From these results it may be interesting to calculate how 

 much moisture a tree loses in winter. The apple tree from which 

 we took these twigs is twelve years old and six inches in diameter 

 through the trunk. It exposes about 120 square feet of surface 

 and, evaporates about 13.5 grains of moisture per day, which is a 

 little more than one gill. This may then explain why it is that some 

 trees are injured during very dry winters. It is a known fact that 

 trees which cannot endure our climate thrive farther east, where 

 the temperature may be the same, but where the climate is more 

 moist. Therefore, the more dry the climate, the more susceptible 

 are trees to injury. The time that there is most danger from this 

 source is during several days of continued freezing weather, when 

 no moisture can be supplied from the roots to take the place of that 

 lost by evaporation. 



It has been noticed frequently that during very cold weather in 

 winter the twigs seem somewhat duller than usual, and sometimes 

 tend to become shriveled in appearance. After a few days of thaw- 

 ing weather, they resume their normal appearance again. This is 

 no doubt due to the fact that during a thaw the equilibium between 

 the sap in the tree and that taken in by the roots is maintained, so 

 Ihat as fast as moisture is evaporated from the twigs and branches 

 sap flows up from the roots and re-establishes the equilibrium. 



It has been thought that the rate of evaporation from trees in 

 winter determines the relative hardiness of different varieties of 

 apples and some other fruits. But experiments, made at the Cornell 

 experiment station, with several varieties of apples of different 

 degrees of hardiness, show that no such relation exists between the 

 per cent, of loss of moisture and the hardiness of the varieties. 



Studies have also been made at Cornell to show that the tender- 

 ness of some trees in dry winter climates may have been due to 

 such an anatomical structure of the bark as cannot resist evapor- 

 ation, and that hardiness is sometimes simply due to a thickness or 

 denseness of the bark. The experiments seem to prove this to be 

 true in some cases, but the investigations have not been carried far 

 enough to give any definite results. 



Wild Flowbrs for the Garden. — When planning for the early 

 flower garden do not forget the wild flowers. Select a moist, shady 

 spot, remove sufficient earth and fill in with carefully selected leaf 

 mold from the forest. Fringe the bed with pretty maidenhair and 

 other small ferns, fill it with spring beauties, anemone, wild hepa- 

 tica and violets. 



The spring is the best time to make a wild dower bed, but as the 

 plants are more hardy than cultivated ones, little difficulty will be 

 experienced in their safe removal at any time if taken up with a ball 

 of earth adhering and kept well watered and shaded. 



