Mistakes to Avoid When Planting a Tree

By Home Improvement Need Staff

The essentials

  1. Call 811 a few days before digging so underground gas, water and other lines can be marked before your shovel hits them.
  2. Keep the root flare visible: the root collar should sit at or slightly above ground level, never buried under soil or mulch.
  3. Dig a wide, saucer-shaped hole no deeper than the root ball; recommended width ranges from 1.5 to 5 times the ball, wider in compacted soil.
  4. Spread mulch 2 to 4 inches deep but keep it from touching the trunk, where it causes decay.
  5. Water daily for the first two weeks, then on a set schedule through the first year, and stake only bare-root or small trees for one year.

A tree is one of the few yard projects that will outlast your time in the house, which makes the first hour with a shovel matter more than it might seem. Most young trees that fail in their first season or two were undone by planting technique or aftercare, not by bad luck. The mistakes below are the ones extension services and arborists see again and again. Skip them, and a modest amount of planning and watering is usually enough to get a young tree established.

Planting Before You Call 811

A shovel can find trouble fast. Around a typical property there may be power, phone, internet and cable lines overhead or buried, along with water, sewer, gas and irrigation lines underground. Cutting through one is dangerous and expensive, and it is entirely avoidable.

Call 811 a few days before you dig, and underground utilities will be marked so you can route around them. Look up while you are at it: a large shade tree planted under overhead power distribution lines will spend its life trimmed back by the utility, which is the classic example of the wrong tree in the wrong place.

Choosing a Spot Without Checking Mature Size

The tree in the pot is not the tree you are buying. What matters is the height and spread at maturity, and whether the site can handle them. Before you shop, sketch your property with pencil and eraser, measure with a tape, and note sun exposure, soil conditions and your hardiness zone.

Purpose should shape the pick as much as space does:

  • Shade. Deciduous shade trees set on the southeast, southwest and west sides of the house shade it through summer, and their bare branches let low winter sun through to help warm it.
  • Wind protection. An evergreen windbreak on the north side blocks cold winter winds.
  • Privacy. A screen needs height and density where it counts, which can mean several smaller trees rather than one large one.

Shading windows or an air conditioner unit can help conserve energy. Short, flowering trees fit under utility lines where a maple cannot. And test the soil before you spend money: a soil test reveals pH and nutrient problems before they become tree problems. State extension services offer soil testing, so it is worth checking what your local program provides.

Planting Too Deep: Why the Root Flare Should Stay Visible

This is the most common planting mistake extension educators encounter, and it kills slowly. At the base of a healthy tree, the trunk widens where it meets the roots. That bulge is the root flare, and it should still be visible after the tree is planted.

Trunk wood and root wood are built differently. When soil or mulch holds moisture against the trunk, the living tissue under the bark stays wet, which disrupts the gas exchange it needs to survive. Over time the buried flare begins to die, decay fungi move in, and the tree can fail at the base even while the crown still looks green. Deep planting also cuts the oxygen reaching the roots, can trap moisture around the root ball, and encourages girdling roots that strangle the trunk as it thickens.

Two habits cause it. First, trees often arrive from the nursery already too deep in their own container or root ball, so brush away the excess surface soil until you find the flare before you dig anything. Second, people dig the hole deeper than the root ball, and the tree settles below grade. Set the root collar, where the uppermost roots meet the trunk, even with the surrounding soil or slightly above it; planting a couple of inches shallow is safer than burying the flare.

Handle the tree by the root ball, never the trunk, since lifting by the trunk can separate the ball from the tree. If a container tree is root-bound, with roots circling the inside of the pot, cut a shallow X across the bottom of the ball and four vertical slices along the sides, or tease the circling roots outward by hand before planting.

Digging the Hole Wrong Shape or Size

The right hole is wide and shallow with sloping sides, more like a saucer than a post hole. Width gives new roots loose soil to spread into; extra depth does not help, because roots establish outward.

How wide is wide enough? Extension guidance differs on the exact figure. Some services call for a hole at least 1.5 times the width of the root ball, closer to 3 times in compacted soil. Others recommend 2 to 3 times as wide, 3 to 4 times as wide for container trees, or as much as 3 to 5 times the diameter of the ball. The common thread is simple: a hole several times the width of the ball, dug wider in compacted soil, gives new roots the easiest path outward. Depth should match the root ball or fall slightly short of it. Digging deeper and backfilling underneath leaves the tree sitting on loose soil that can settle, sinking the flare below grade, and disturbing the soil at the bottom of the hole does the root ball no favors.

Backfill with the soil you dug out. Mixing amendments into the hole alone can backfire, because roots may circle that improved pocket instead of spreading into native soil; if you want to improve the soil, work amendments through an entire planting bed instead. Firm the backfill gently to remove air pockets, using water or the flat of the shovel rather than stomping, which compacts the soil and squeezes out the pore space roots need. Leave the top of the root ball uncovered, and build a low berm of soil at least 3 inches high around the edge of the hole to hold water while it soaks in.

Mulch Volcanoes and Other Mulching Mistakes

Applied correctly, mulch does real work: it insulates the soil against temperature swings, holds moisture, suppresses weeds that would compete with young roots, prevents compaction, and keeps mowers and string trimmers away from the bark. Applied badly, it buries the trunk.

The pattern is simple. Remove grass in a circle about 3 feet across around the tree, up to 10 feet for a large tree. Spread a 2 to 4 inch layer of organic mulch, such as shredded bark or wood chips, though some extension services advise keeping it to 3 inches or less. Then pull the mulch back so it never touches the trunk.

A mound of mulch piled against the bark, sometimes called a mulch volcano, causes the same wet-bark decay as planting too deep. Roots can also grow into the mulch itself and eventually girdle the trunk. If you cannot see the root flare, there is too much mulch.

Skipping the First-Year Watering Plan

New trees die from too little water and from too much, and a schedule matters more than the volume of any single soaking. For container-grown trees, water daily for the first two weeks, then every three to seven days through the first year. For balled-and-burlapped trees, the guidance is a generous watering every seven to ten days during dry weather in the first year. The soil should stay moist, not soggy.

Exact needs vary with climate, soil and rainfall, so check the soil a few inches down before each watering instead of trusting the calendar alone. Water slowly at the dripline, the outer edge of the branches, so moisture soaks in where the roots are headed rather than running off. A hose with an adjustable nozzle makes this routine easier, and it helps to know what to check before you pay for a garden hose, since diameter and length determine how much water actually reaches the tree.

Pro tip

Set a recurring reminder such as Water Wednesdays so the first-year watering schedule survives a busy week.

Staking When You Don’t Need To

Staking is mainly for bare-root and small trees, and only for one year. If you stake, install two opposing stakes outside the root mass, loop flat canvas straps with grommets around the trunk, and run the wire through the grommets so it never presses on the bark. Ties left on past that first year can rub and damage the trunk, so mark the removal date when you set the stakes.

Neglecting the First Two Years of Care

What you do in a tree’s first few years affects its shape, strength and even its lifespan. A few habits that earn their keep:

  • Remove tags, labels and any twine on the branches; left in place, they can girdle limbs as the tree grows.
  • Prune only broken, dead, or crossing and rubbing branches at planting. Structural pruning should wait at least three years so the tree can put its energy into roots and trunk wood.
  • Watch for pests and disease. Both vary by region and can be hard to diagnose, so a certified arborist is worth calling if a young tree starts declining. Certified arborists do the hands-on work of planting, pruning, fertilizing, pest treatment and removal, while consulting arborists focus on diagnosing problems and recommending care.

Timing helps too. Fall, winter in unfrozen soil and early spring are the best planting windows, while summer planting stresses a tree in full leaf. A handful of fleshy-rooted species, including dogwoods, magnolias, willow oaks, tulip poplar and yellowwood, should go in the ground in spring. If you buy a tree but cannot plant it right away, keep it in a cool, shaded spot and water it so the roots do not dry out. Fall is also a good season to handle the rest of your outdoor upkeep, and our fall home maintenance checklist rounds up those jobs.

Common questions

How deep should I plant a new tree?

Dig no deeper than the root ball and set the root collar even with or slightly above the surrounding soil. The root flare should stay visible after backfilling and mulching.

When is the best time to plant a tree?

Fall, winter in unfrozen soil, and early spring are the best windows. Summer planting stresses a tree in full leaf, and fleshy-rooted species such as dogwoods and magnolias do best in spring.

How often should I water a newly planted tree?

Container-grown trees need daily watering for the first two weeks, then every three to seven days during the first year. Balled-and-burlapped trees do well with a generous watering every seven to ten days during dry weather.

Do new trees always need to be staked?

No. Staking is mainly for bare-root and small trees, and only for one year. Use two opposing stakes with flat canvas straps, and remove the ties at the one-year mark.

This guide is general information, not professional advice. Follow the manufacturer’s instructions and your local building codes, and hire a licensed professional for electrical, gas, structural or roofing work.

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