Raising the soil level around a tree’s back is not recommended. Although large piles of mulch often are found around tree roots and trunks, that practice is harmful to tree health. Rather than placing a raised bed around a willow tree, then it’s ideal to create the illusion of a raised bed using one of many practices.
Willow Root and Trunk Systems
It is a common misconception that tree roots grow deep as opposed to long. A willow tree’s active origins, such as those of most trees, are within the top 3 feet of soil. The largest and most productive origins are in the top 1 foot of soil. This is since roots seek both moisture and oxygen, which can be found together only in the top layers of soil. When soil or mulch is stacked around a tree’s trunk, it cuts off the oxygen supply to your tree roots. In addition, it poses moisture to areas of the trunk that aren’t built for this, weakening the bark and lower trunk region.
1 way to create the illusion of a raised bed is to excavate around the foundation of the willow tree. It is important to maintain the excavation from the drip station, that’s the region directly under the outside limit of branches from which rainwater drips. Go out of that region, and use a garden spade to break up the soil around the tree’s base carefully. Do not to dig into the origins; the goal is just to loosen the soil to make planting easier. If old leaf mulch can be found, place a layer over the surface of the soil, and incorporate it into the loosened soil to encourage aeration. Plant flowering plants directly into the ground outside the drip station.
An alternative is to construct a brief wall with tall plantings around the drip zone working with any landscaping obstacles you find appealing. Preserve the wall at about 12 inches tall or lower. Directly behind it, then utilize the excavation method previously explained if you want to plant tall ornamental plants. Choosing plants that have long stems and high flowers creates the illusion of a raised bed without damaging the willow’s fragile root system.
It can take up to five years to see the consequences of damage to a tree, according to North Carolina State University. A neighbor’s tree with a raised bed might seem perfectly fit, but given time the tree will weaken, and its recovery is not guaranteed. In order to protect the health of the willow tree and buildings and plants within the tree’s fall station, it’s ideal to sacrifice having a raised bed all around your willow tree.