The short answer
To plant a tree, dig a hole two to three times wider than the root ball but no deeper. Set the tree so the root flare sits at or slightly above the soil line. Loosen any circling roots, backfill with the soil you dug out, and water deeply. Finish with 2 to 4 inches of mulch kept off the trunk. Then water every week through the first dry summer.
That's the whole job. The steps below explain each part, plus what changes when you plant in Oregon clay.
When to plant a tree in western Oregon
Fall is a great time to plant in the Willamette Valley. The soil is still warm from summer, and the fall rains take over most of the watering. Roots keep growing through our mild winters, so the tree is better rooted when the dry season arrives. Our fall planting guide for Oregon covers the timing in more detail.
Late winter and early spring are the next best windows. Summer planting works too, but you'll need to water much more often. Avoid planting when the soil is frozen or so wet that it sticks to your shovel in clumps.
What you'll need
- A round-point shovel and a garden fork
- A hose or watering can
- Coarse wood chip or bark mulch
- Pruners or a sharp knife for roots
- Two stakes and soft, flexible ties, only if your site needs them
How to plant a tree, step by step
- Call 811 before you dig. It's free, and it's the law in Oregon. Utility crews will mark buried gas, power and water lines. Call at least two business days ahead. Also look up for power lines and pick a spot with room for the tree's mature size.
- Find the root flare. The root flare is where the trunk widens into the top roots. In nursery pots it's often buried under extra soil. Gently scrape soil off the top of the root ball until you find it. This tells you how deep to dig.
- Dig wide, not deep. Make the hole two to three times as wide as the root ball. Dig only as deep as the distance from the root flare to the bottom of the root ball. Most new roots grow sideways in the top foot of soil, so width matters far more than depth. Leave the bottom of the hole firm so the tree doesn't sink.
- Rough up the sides. In clay soil, a shovel can leave the walls of the hole slick and smooth. Roots have trouble breaking through. Scratch the sides with a garden fork to break that glaze.
- Remove the container and loosen roots. Slide the tree out of its pot. If roots circle the outside of the root ball, tease them loose with your fingers. Cut any that are thick and wrapped tight. Circling roots left alone can girdle the tree years later. For balled and burlapped trees, set the tree in the hole first, then cut away the wire basket, twine and as much burlap as you can reach.
- Set the tree at or slightly above grade. Place the tree in the center of the hole. The root flare should sit level with the surrounding soil or an inch or two higher. Lay your shovel handle across the hole to check. A tree planted too deep is one of the most common reasons new trees fail.
- Backfill with native soil. Refill the hole with the same soil you dug out. Break up large clods as you go. Skip heavy amendments like bagged compost or potting mix in the hole. Rich, fluffy soil in the hole encourages roots to stay put instead of spreading into the ground around it. In clay, it can also hold water like a bathtub.
- Water it in. Fill the hole halfway, then water slowly to settle the soil and remove air pockets. Finish backfilling and water again. Don't stomp the soil down hard. Build a low ring of soil around the outer edge of the hole to hold water over the root ball.
- Mulch 2 to 4 inches deep. Spread mulch over the planting area, as wide as you can. Keep it pulled back a few inches from the trunk. Mulch piled against the bark, often called a mulch volcano, holds moisture against the trunk and invites rot and pests.
- Stake only if needed. Most container trees stand fine on their own. Stake only if the tree leans, the root ball is loose, or the site is very windy. Use two stakes outside the root ball and soft ties set low on the trunk. Allow some movement, since a little sway builds a stronger trunk. Remove stakes after one growing season.
Hold off on fertilizer at planting time. Let the roots settle first. Prune only broken or dead branches for now.
Oregon notes: clay, wet winters and dry summers
Much of the Willamette Valley sits on heavy clay. Clay holds nutrients well, but it drains slowly. Before you plant, dig a test hole and fill it with water. If water is still standing the next day, the spot drains poorly.
- Poor drainage: Plant the tree a little higher, with the root flare 2 to 3 inches above grade, and mound soil gently up to the root ball. Or pick a tree that tolerates wet feet, like Red Sunset Maple.
- Wet winters: Don't dig or plant in saturated clay. Working wet clay squeezes out the air and leaves it hard as brick when it dries. Wait a few dry days.
- Dry summers: Our rain mostly stops from July through September. A tree planted in fall still needs regular deep watering its first summer, even if it looked fine all winter.
First-year watering schedule
New trees dry out from the root ball first, so aim the water there. A slow trickle from a hose for 15 to 30 minutes works well. Here is a simple guide for a tree planted in fall in western Oregon.
| Season | How often to water |
|---|---|
| Fall, after planting | Weekly until steady rain starts |
| Winter | Usually none. Water only during long dry spells. |
| Spring | Weekly once the rain tapers off |
| Summer | One or two deep soaks a week, more in heat waves |
To check, push a finger or trowel into the root ball. If it's dry 2 inches down, water. If it's soggy, wait. Too much water is as harmful as too little in clay soil. Keep up deep summer watering for the first two to three years while roots spread.
Frequently asked questions
How deep should I plant a tree?
Plant it no deeper than it grew in the pot. The root flare should be at or slightly above the soil line. In poorly drained clay, set it 2 to 3 inches high.
Should I add compost or fertilizer to the planting hole?
No. Backfill with the native soil you dug out. Compost works better spread on top as mulch. Skip fertilizer at planting and reassess in spring.
Do I need to stake a new tree?
Usually not. Stake only if the tree can't stand on its own or the site is very windy. Use soft ties, allow some sway, and remove the stakes after one growing season.
Get help choosing and planting your tree
The Nursery Outlet grows trees at our nursery in Woodburn and serves homeowners and landscapers across the Willamette Valley, from Salem to the Portland metro area. If you're not sure which tree fits your yard or soil, contact our team or stop by the nursery. Local delivery and installation are available too. We're happy to help you pick a tree and get it in the ground the right way.