Why is the tree root flare important in planting and aftercare?

• A. The flare should be buried below the soil line to enhance stability
• B. The flare should be cut flush with soil line
• C. The flare should be covered with mulch to protect it
• D. The flare should be at or above the soil line; burying it promotes girdling roots and poor establishment

Answer: (D)

The root flare is the place where the trunk widens into the root system, and it should sit at or just above the soil surface. Keeping the flare visible at or above the soil line ensures roots have space to spread and receive adequate oxygen, which supports healthy establishment after planting.

When the flare is buried, roots can begin to circle and constrict the trunk, creating girdling roots that choke the tree’s access to water and nutrients and lead to decline over time. Burial also traps moisture against the trunk, increasing the risk of trunk rot and pest or disease problems, and it can delay or impair root establishment.

So, the recommended practice is to position the tree so the flare is at or slightly above the soil line, and to avoid piling soil or mulch over it. During aftercare, keep mulch away from the flare, water appropriately, and avoid compacting soil around the root zone.