If the soil feels wet or forms and holds a ball when squeezed in the hand, the soil does not need to be irrigated. Trees do best when there is time for the soil to drain and dry slightly between irrigations. Many woody plants are damaged by early fall and late spring frosts. Depending on the time of year, frost injury is characterized by blackening or browning of foliage or newly emerged shoots and flowers all over the plant. In areas where frost pockets develop, only the lower plant parts may be affected.
Plants are most susceptible to frost injury during the spring flush of growth.
Spring frost injury often is more noticeable than fall injury, especially when new shoots of spruce droop and redden or fir shoots droop and turn light brown. Flowers also are damaged or killed on plants such as lilac and crabapple. Spring frost damage to evergreens is characterized by a downward curling of shoot tips. Affected tips may turn red or brown within one or two weeks. A severe fall frost can cause serious damage or death to parts of trees that have not hardened off.