Influence of Pure Mulches on Survival, Growth and Vitality of Containerized and Field Planted Trees

Abstract

Abstract Mulching as a means of reducing soil moisture stress, suppressing weed growth and improving soil fertility is widely recognised throughout the arboricultural, nursery and landscape industry. The influence of a pure mulch, i.e. mulch derived solely from one tree species, has received little study. The purpose of this research was to evaluate pure mulches derived from European beech (Fagus sylvatica L.), common hawthorn (Crataegus monogyna JACQ), silver birch (Betula pendula ROTH.), common cherry (Prunus avium L.), evergreen oak (Quercus ilex L.) and English oak (Q. robur L.) on survival and growth of two commonly planted urban trees (European beech, common hawthorn) following containerization and two economically important fruit trees (apple (Malus cv. Gala), pear (Pyrus communis ‘Concorde’) following field transplanting. In the case of beech, a highly sensitive transplant species, survival rates were increased from 10 to 70% following containerization. In the case of hawthorn, a transplant tolerant species, no difference in survival rates between mulched and non-mulched controls were recorded, however, marked differences in growth between, and compared to, non-mulched control trees existed. In field planted apple and pear trees crown volume and fruit yield could be increased by 53 and 100%, respectively, by application of an appropriate pure mulch. Allelochemical testing of water soluble extracts of each pure mulch indicated positive benefits in terms of enhanced seed germination and seedling relative growth rates with one exception — a mulch derived from beech where no positive benefits were found. In conclusion, pure mulches offer positive benefits for those involved in the care and maintenance of urban trees as well as nursery, forestry, orchard and horticultural crop production. Pure mulches require no capital investment and only small adjustments to standard management aftercare procedures.