Planting a tree is one of the best long-term investments you can make in your yard—but in Colorado’s dry, high-altitude climate, timing matters just as much as species and location.

“Right tree, right place, right time—get all three right and that tree will probably outlive you.”

Most homeowners only get one or two chances a year to plant in ideal conditions. Here’s how to pick the best season, avoid stress, and give your new tree a strong start.

Colorado’s Climate: Why Timing Matters

Along the Front Range and in much of Colorado, trees deal with:

• Intense sun and big temperature swings
• Low humidity and drying winds
• Periodic drought and watering restrictions
• Soils that can be compacted, alkaline, or both

Newly planted trees don’t yet have deep, established root systems. Plant at the wrong time and they struggle to keep up with water loss, leading to stress, dieback, or even failure in the first year.

That’s why we focus on planting when soil is workable, roots can grow, and above-ground stress is lower.

Best Time #1: Early to Mid Spring

For most species, early to mid spring is one of the best planting windows in Colorado.

Aim for:

• Soil that’s thawed and workable
• Daytime highs mostly in the 50s–60s°F
• Before or right as buds begin to swell and leaf out

Why spring works well

• Cool air temperatures reduce water loss from leaves.
• Warming soil encourages new root growth.
• Trees have the entire growing season to establish before winter.

Spring planting tips

• Water deeply after planting and continue on a regular schedule, even if we get a late snow.
• Add 2–3 inches of mulch over the root zone (but not against the trunk) to conserve moisture.
• Avoid heavy fertilization that first season; the priority is roots, not fast top growth.

Best Time #2: Early Fall (Late August–October)

The other excellent window is early fall, from late August into October, depending on elevation and forecast.

In fall:

• Air temperatures cool down
• Soil is still warm from summer
• Trees naturally start directing energy to root growth

This combination is ideal for establishing roots with less heat stress on the canopy.

Fall planting tips

• Plant at least 4–6 weeks before the ground typically freezes.
• Water consistently until the soil freezes, even after leaves drop.
• Apply a good mulch layer to help moderate soil temperature and lock in moisture.

Many Colorado trees planted in early fall go into winter with stronger root systems than trees planted in late spring or summer.

Times to Avoid Planting

There are a few periods when it’s best to wait.

Mid-summer heat

Planting in July or early August often means:

• High temperatures
• Intense sun and wind
• Higher water demand than a new root system can supply

If you must plant in mid-summer, expect to be on a very consistent deep-watering schedule and consider temporary shade for sensitive species.

Frozen or waterlogged soil

Avoid planting when:

• The ground is frozen hard enough that you can’t dig properly
• Soil is extremely muddy or saturated, which can lead to poor structure and airless planting holes

In those cases, it’s usually better to wait for a proper spring or fall window.

Container, Balled-and-Burlapped, and Bare-Root Trees

Your planting timing also depends on how the tree is grown and sold.

Container-grown trees

• Most flexible planting window
• Can usually be planted anytime the ground isn’t frozen
• Still do best in spring or early fall for less stress

Balled-and-burlapped (B&B) trees

• Often heavier and more sensitive to handling
• Prefer spring or early fall when they can rebuild roots before heat or deep cold

Bare-root trees

• Typically planted very early spring while still dormant
• Need careful handling and immediate planting so roots don’t dry out

If you’re not sure which type you’re buying, ask your nursery or certified arborist—they can recommend the safest timing for that stock.

Matching Species to Season

Some trees handle spring or fall planting better than others.

For example:

• Many native species, like our native Denver cottonwoods, are fairly forgiving if planted with proper care.
• Certain ornamental or marginally hardy species may be safer in spring so they have a full growing season before their first winter.

When in doubt, ask which species are best suited for your specific site, elevation, and exposure. A well-chosen tree planted in a good window will establish faster and require less rescue watering later.

How to Prepare the Site Before Planting

Regardless of when you plant, good site preparation is critical:

1. Call before you dig. Have underground utilities located and marked.
2. Dig wide, not deep. The planting hole should be 2–3 times as wide as the root ball, but only as deep as the root flare.
3. Find the root flare. The point where the trunk widens at the base should sit right at or slightly above finished grade.
4. Backfill with existing soil. Avoid creating a “soft” pocket of rich soil surrounded by hard native soil; that can trap roots.
5. Water in thoroughly. Eliminate air pockets and settle soil around the roots.

For more on what happens after planting, you can also read about how trees reproduce with help from their friends and how that influences long-term tree health.

Watering New Trees in Colorado

Newly planted trees need regular, deep watering during their first 2–3 years:

• Water slowly at the drip line, not just at the trunk.
• Let the soil dry slightly between waterings, but don’t let it become bone dry.
• Adjust your schedule for rainfall, soil type, and local watering rules.

In winter, remember to winter-water on warmer days when the ground isn’t frozen—especially for evergreens and fall-planted trees.

When to Ask for Help

If you’re unsure about timing, species choice, or site conditions, it’s worth talking with a professional.

A certified arborist can:

• Recommend the best planting window for your specific location
• Help you select species that fit your soil, space, and goals
• Plant the tree correctly and set up an aftercare plan

Planting at the right time of year is one of the easiest ways to stack the odds in your favor. Get the timing right, and your new Colorado tree has a much better chance of becoming the healthy, long-lived shade tree you’re hoping for.