Use trunk flare to find out how deep to plant a brand new tree

“My neighbor informed me my tree was planted too deeply. How do I decide the right planting depth?”

— Nicole Cramer, Glenview

Timber are sometimes planted too deep by householders and professionals, so it’s a good suggestion to know the best way to place a brand new tree on the correct depth.

Lately planted timber that resemble phone poles popping out of the bottom are most likely planted too deep. Usually, this is not going to trigger issues within the early years, however it may be a significant factor within the decline and even loss of life of the tree sooner or later.

Take a look at the bottom of the tree the place it meets the bottom to find out in case your tree is on the correct depth. Mulch must be pulled a pair inches away from the bottom of the tree. Nearly all of the roots will develop within the prime 12 to 18 inches of soil, although this varies relying on the kind of tree and backyard soil. The tree’s root system will develop at a shallower depth in heavy clay soils versus better-drained loamy or sandy soils.

If the tree is planted too deep, new roots may have problem creating due to a scarcity of oxygen. A tree that’s planted too deep and doesn’t die over time could by no means attain its full potential.

Use the trunk flare as a substitute of the foundation ball prime to information you in figuring out the planting depth of a brand new tree. The trunk flare is the world on the base of a tree that swells and merges with the roots. Look down the trunk till you see it begin to widen on the base — that is the trunk flare.

If the trunk flare is buried within the root ball, plant the tree greater within the gap and punctiliously take away the surplus soil above the foundation system. Watch out to keep away from breaking apart the foundation ball and damaging any roots or the trunk of the tree as you shave off extra soil. Use a pointy, flat spade to do that and push the spade towards the trunk of the tree as you take away the soil. The trunk flare must be seen when planting is accomplished.

In heavy clay soils, I favor to plant timber excessive — with the trunk flare 2 to three inches above current grade. When soils are sandy and really effectively drained, I typically place the trunk flare 1 to 2 inches above grade. If the foundation ball seems to be unfastened, take away the wire basket and burlap after the tree is positioned within the planting gap.

Normally, it’s best to not amend the soil used to backfill a planting gap. Use the soil that was dug out of the planting gap to fill in across the root ball. I’ve planted timber this fashion with good outcomes.

In some conditions, changing the heavy clay backfill soil with new soil or closely amending it may be detrimental. Water motion by way of the soil might be impeded when it enters soil with one kind of texture (a brand new or amended backfill) after which meets the prevailing backyard soil. Extreme water can accumulate within the backside of the planting gap and result in root suffocation and rotting of the roots. Roots are inclined to develop within the planting gap the place there may be higher aeration, moderately than rising out into the encircling soil.

It’s a good suggestion to dig a large planting gap, as it’ll cut back soil compaction across the root ball and enhance soil aeration, making situations higher for roots to develop. When possible, make the planting gap two to a few instances the width of the foundation ball. Make the edges of the opening slanted with a gradual slope upward so it’s simpler to backfill.

Work the soil in across the root ball so there are not any remaining air pockets. If the complete mattress has been amended, it’s much less vital to dig a large planting gap. It’s OK to amend the highest layer of soil round a newly planted tree.

For extra plant recommendation, contact the Plant Data Service on the Chicago Botanic Backyard at plantinfo@chicagobotanic.org. Tim Johnson is senior director of horticulture on the Chicago Botanic Backyard.