How can I improve the soil conditions around my tree to help it grow?
Vertical mulching is a technique used to help alleviate soil compaction in the critical root zones of trees. It is also effective to improve soil conditions after construction projects. Compacted soil can be detrimental to a tree’s health by reducing the movement of water and oxygen—both vital to the tree’s well–being—throughout the soil. Vertical mulching involves removing columns of poor-quality soil around the tree in a radial or grid pattern. Holes are then filled with compost. Vertical mulching provides many benefits, including necessary nutrients, soil aeration and deeper water penetration.
Should I fertilize my trees?
Young trees, like those planted by the Be A Smart Ash program, are still in their establishment phase and focusing on root growth. Nitrogen fertilizer, the most common type of fertilizer used for trees, generally increases canopy growth, resulting in a decrease in root growth, so we do not recommend fertilizer for young trees. If soil conditions are poor, vertical mulching is a good way to improve the soil without using fertilizer. One of best ways to help your tree is to continue to replenish the organic mulch layer around your tree, as it will break down over time and naturally add nutrients to the soil. Our friends at CSU Extension have more information on fertilizing shade trees.
Can I put rocks instead of mulch around the base of the tree?
Please don’t! Rocks used as ground cover are detrimental to trees and shrubs. Rocks retain heat, which in turn raises the soil temperature and increases evaporation, leading to stressed, thirsty trees that require even more water. Additionally, rocks don’t provide any essential nutrients and can change the soil chemistry, which can be unfavorable for many trees. While rocks and xeriscape lawns can be a way to conserve water in other areas of your garden, it’s essential that the area around your tree roots is covered with mulch or other organic material to provide those much-needed nutrients to the soil.
Can I allow grass to grow around the base of the tree?
We do not recommend grass around the base of the trunk. Grass competes with young trees for moisture and nutrients in our already water-scarce climate. Additionally, having grass close to your tree increases the risk of mechanical damage to the trunk from lawn mowers or string trimmers. A ring of mulch around the base of the tree is the best ground cover in our urban setting.
My tree was planted in a tree pit/tree grate. Do I need to do anything extra to help the tree grow?
Yes! Your tree will likely require more water than what we normally recommend because of the surrounding pavement/metal. Pavement and metal retain more heat, which raises the temperature, increasing evaporation. It’s important to check the soil moisture to determine when your tree needs water in these types of planting locations.
It snowed and now my tree is bending over. What should I do?
Particularly wet and heavy snow can catch on the branches of young trees, causing them to bend and sometimes break. When this type of snow occurs, gently shake the branches of the tree as soon as possible to relieve the weight and prevent damage. If a branch is broken, prune the branch to create a clean cut if it’s something you can safely reach, or contact a licensed tree care professional to help with the pruning or treatment of your tree.