They are applied either on the foliage or on the soil. Liquid fertilizers are important in production of nursery stock, particularly as additives in spray operations. Landscape and grounds personnel use liquid fertilizers extensively for deep root feeding of trees and shrubs. Objectives of Fertilizer Application Fertilizers may help improve the appearance and condition of ornamental trees and shrubs. Increased vigor may make the plants more resistant to attack by disease organisms and insects.
Many factors influence the fertilization program of plants in the landscape.
Unlike similar plants growing in the nursery, landscape plants are often growing under stress. Fertilization practices leading to satisfactory plant growth must take into account these stresses. Fertilizer response varies with the plant and the environment. Soil fertility, aeration, drainage, exposure to sun and wind, temperature of the site, and proximity to buildings, walks and streets are but a few of the many factors that influence plant growth. The purpose of fertilizing landscape plants during the first year or two after transplanting is to increase height, width and caliper.