Posted by Nathaniel Hardy on Tue, May 22, 2018 @ 6:16 AM
A new video released by Citygreen demonstrates the importance of understanding soils and watering to prevent street tree failure. Citygreen Consultant, Nathaniel Hardy, visits a stressed street tree located in the dry climate of the ACT. Despite being irrigated with a suitably large volume of water, the tree is lacking outer foliage with bare, dead branches clearly visible. So, why is the tree failing to thrive despite receiving the required volume of water?
Nathaniel draws attention to the finely-textured, clay-filled soil in the rectangular garden bed surrounding the tree. A circular mulch ring around the tree is simply not big enough to cope with the volume of water being provided, so much of the water is escaping into the larger garden bed and then onto the surrounding pavement. Because the pavement is only slightly elevated, water does not have a sufficient opportunity to penetrate the fine soil and irrigate the roots below. Instead, we see a dry, caked soil surface which has become largely impervious to water.
As the video demonstrates, simply providing the required volume of water is not enough. Understanding the character of your soil and the runoff behaviour of water provided is integral to providing an environment in which street trees can thrive.