When planting trees and shrubs, one of the most common—and costly—mistakes is planting too deep. While it may not seem like a problem at first, improper planting depth can lead to long-term stress, disease, or even plant failure.
Understanding proper planting depth and mulch placement helps trees and shrubs establish strong root systems and thrive for years to come.
Quick Planting Depth Tips
- Always locate the root flare before planting
- The root flare should sit just above soil level
- Never pile mulch against the trunk
- Planting slightly high is better than too deep
Why Planting Depth Matters
Trees and shrubs must be planted at the correct depth to develop healthy roots and long-term stability.
- Find the root flare: The root flare is where the trunk widens at the base and roots begin to spread. This flare should remain visible just above the soil surface. Burying it can lead to rot and root suffocation.
- Too deep causes problems: Trees planted too deep often develop roots that grow upward in search of oxygen. These girdling roots can eventually strangle the trunk and reduce water and nutrient flow.
Avoid Loose Soil Beneath the Root Ball
When planting, it’s important that the soil beneath the root ball is firm and undisturbed. If loose soil is left underneath, the tree or shrub can settle after watering or rainfall.
This settling often causes plants that were originally planted at the correct depth to sink too low, burying the root flare and creating long-term health problems.
To prevent this, dig the planting hole only as deep as the root ball and make sure the base is solid. It’s better to plant slightly high than risk the plant settling too deep.
Checking Container-Grown Plants
Many container-grown trees and shrubs are planted too deep in their pots.
Before planting, gently remove soil from the top of the root ball until the root flare is visible. You may need to plant the tree slightly higher than it sat in the container.
Proper Mulching Techniques
Mulch is highly beneficial when applied correctly.
- Apply a 2–3 inch layer of mulch around the planting area to conserve moisture and suppress weeds.
- Keep mulch several inches away from the trunk to prevent rot, insect problems, and disease.
Tip: Mulch should resemble a donut, not a mound, with open space around the trunk.
Giving Trees and Shrubs a Healthy Start
Taking a few extra minutes to plant at the proper depth and apply mulch correctly gives trees and shrubs the best chance to establish and thrive.
If you’re ever unsure about planting depth or technique, our staff is always happy to help you plant with confidence.