Action: Cover the ground with straw after tree planting
- One replicated, randomized, controlled study in the Czech Republic found that covering the ground with straw, but not bark or fleece, increased the growth rate of planted trees and shrubs.
Covering the ground with straw during tree planting can decrease evaporation and germination of competing species, and thus increase the establishment rate of planted trees.
Supporting evidence from individual studies
A replicated, randomized, controlled study in 2000-2005 in temperate broadleaf woodland in the Czech Republic (1) found that covering the ground with straw mulch increased the growth rate of planted trees and shrubs, but covering with bark or fleece mulches did not. Five years after planting, the average growth of trees and shrubs was higher with straw mulch (226 cm) than with bark mulch (124 cm), fleece mulch (100 cm) or no mulch (80 cm). In 2000, seedlings of a mixture of 128 tree and 190 shrub species were planted in each of four 600 m2 plots. Each plot was divided into four 150 m2 subplots that were randomly assigned to four treatments: straw mulch (planting and covering the whole area with a 0.3 m layer of straw mulch); bark mulch (planting in a previously established grassland and applying a 0.2 m layer of fresh bark in 0.4 m rows); fleece mulch (planting in a previously established grassland and applying layers of 0.4 m wide synthetic fleece in rows); no mulch (planting in a previously established grassland). Plants were measured in 2005.