Fall is approaching and it's almost prime tree-planting season! While you can plant a tree at almost any time of the year, the fall is a great time with cooling days and nights, more rainfall, and the tree already slowing its above-ground growth in anticipation for winter.
But it’s vital to know the right way to do it for success!
Watering, soil, timing, location, and pruning are all factors to remember! But proper planting depth is a major key to a successful transplant.
The right depth is vital to a long-term, stress-free healthy tree!
Roughly 80% of a tree's root system is located in the upper 18-24 inches of the soil surface, and extending out for many feet away from the trunk. Roots like to grow in the warmer soils closer to the surface where they can grow out in all directions to find food and water while stabilizing the above-ground portion of the tree.
Planting new trees are most often are planted too deep. Planting too deep results in those feeder roots smothering due to lack of oxygen which can lead to deterioration of the bark at the soil line and also kill the tree.
But planting too shallow does occur leaving the surface roots to become exposed (often when the soil has washed away, or the root ball wasn’t planted deep enough), you’ll end up having your tree's main support system dry out, be eaten by rodens and insects, and be exposed to the hot sun and chill in the winter.
Despite sometimes adapting to a slightly deep or slightly shallow depth in the ground, you will drastically shorten your tree's life expectancy!
Trees with tap roots may survive being planted too deeply, but they will be drastically compromised and their buried bark will suffer. Most trees have roots that fan out and anchor the tree but feeder roots need healthy soil that is well-drained and has oxygen and easy-to-access moisture.
Some trees even can sprout roots where the soil is touching them, causing problems later on. Especially with grafted trees.
Even just a few inches off and it can spell doom!
A properly planted tree will have its trunk free and clear and show a slight flare (root flare). If your tree trunk goes straight into the ground, it may be planted too deep. Carefully remove the topsoil at the trunk and find the place where the root flare is and use that at the proper planting height.
For bareroot trees - you’ll see a change in color or texture between the above-ground bark layer and the below-ground portion. And you may still see some soil at the transition. Also, look for the root flare. If you are working with bareroot plants be sure to plant all roots just under the soil surface and not bury them too deeply. Many times, the planting depth is visible on a bare root plant showing where they were grown at the nursery. Plant by fanning the roots out over a mound at the bottom of the hole and backfill until the level is correct. Then fill with moist soil and gently, but firmly pack it down.
Many trees are grafted onto special rootstocks that help them withstand pests, diseases, and temperatures, and control their size among other perks. The graft on a new tree will often be just a few inches above where the soil level is. Planting too deep and even covering this graft (often looking like a slight dogleg or angle) with soil will smother the roots and kill the tree and its scion.
Another kiss of death besides planting too deep or shallow is the addition of mulch up against the trunk of the trees and shrubs. Known as "Mulch Volcanos", having too much mulch will have the same effects as having too much soil. Mulch is great over the roots of plants, but not against the stems of the plants above ground.
Adding a 3-4 inch layer of arborist bark chips over the soil surface right after planting helps maintain soil moisture more regularly, keeps the surface roots cool, and insulates them from the winter chill. The mulch breaks down and enriches the soil.
Do not cover the crowns of ornamental grasses, perennials, or Roses, or fill the interiors of shrubs with mulch and soil either. You will create just as many problems as you are trying to solve.
Proper planting and planting depth are paramount to having a lasting leafy legacy in your yard! And Nature Hills is here to help you every step of the way!
Get ready for the fall planting season now and you and your landscape will reap the rewards for years to come!