WINTER PROTECTION AND MULCHING 101 



leaves and especially from the lower part of such plants as the roses 

 which are particularly sensitive to this type of evaporation. It is for 

 this reason that plants which do not have well-ripened wood like the 

 golden bell and certain varieties of the deutzia are subject to injury be- 

 cause of this evaporation. Other plants like the bush honeysuckle 

 and lilacs which succeed in developing thoroughly ripened wood before 

 winter approaches do not suffer so much. There are two important 

 sources of injury (outside of the gnawing by animals) which can cause 

 plants to be injured during the winter months and as a protection 

 against which mulching is necessary. The first is abnormal evapora- 

 tion from the roots and stems of plants that are in exposed situations, 

 and the second a liability of being heaved from the ground where a 

 clay loam soil is subjected to violent changes of freezing and thawing. 

 It is for this same reason that standard roses and climbing roses are 

 frequently lost during the winter months because they are protected 

 by a thin covering of straw, and evaporation is allowed to continue, 

 when, in reality, they should be taken down and buried in soil which 

 remains moist throughout the winter months and thus protects the 

 stems against evaporation. 



Sources of Winter Injury, and Remedies. One source of winter 

 injury is a heaving in clayey soils which exposes roots of small and newly 

 transplanted plants. This may be remedied by applying a ground mulch 

 of straw litter or manure over the entire area immediately around the 

 trees and covering the area of root growth. Another source is pre- 

 mature activity of the sap, due to the warmth of the sun's rays. If the 

 ground is frozen hard and deep, and sun and severe winds strike ever- 

 green plants they will " scorch " or dry out because sap cannot flow from 

 the roots to take the place of that evaporated. Many evergreens which 

 are exposed to severe winter conditions are in reality killed during the 

 months of January and February; but the damage done does not be- 

 come evident until time for spring growth to begin during the months 

 of April and early May. If the evergreens which have been killed 

 during the winter months in the nursery are dug and shipped to owners 

 of estates at a time prior to spring growth and prior to a time when it is 

 possible for a nurseryman to determine whether or not the plant is in a 

 normal growing condition, plants killed in this manner (because of the 

 lack of winter protection) do not show the injury until the growing 

 season, at which time, with the beginning of warm growing weather, the 



