If you’re wondering when to plant a tree in Colorado, you’re asking the right question to ensure your tree thrives. The best time for planting is crucial in our unique climate, where timing can mean the difference between a struggling sapling and a robust, established tree.
Colorado’s weather presents specific challenges, from late spring frosts to dry summer winds. Picking the perfect planting window gives your new tree the best possible start. It allows the roots to settle in before extreme weather hits.
This guide will walk you through the ideal seasons, specific month-by-month advice, and simple steps for success.
When To Plant A Tree In Colorado – Best Time For Planting
The short answer is that fall is generally the champion season for planting most trees in Colorado. Spring is a very close second, while summer and winter are not recommended. Let’s break down why.
Why Fall Planting is Often Ideal
Fall, specifically from mid-September through October, offers a sweet spot for root growth. The air is cooler, but the soil remains warm from the summer sun.
This combination encourages roots to grow and establish themselves without the stress of supporting new top growth or fighting summer heat. The tree can focus its energy underground.
Benefits include:
- Less heat stress on the tree.
- More consistent soil moisture from autumn rains and snowmelt.
- A head start on root establishment before the next summer’s drought.
- Fewer problems with pests and diseases that are less active in cooler weather.
The Case for Spring Planting
Spring, from late April to early June, is the other excellent option. It works well for many species, especially those less tolerant of colder fall temperatures when first planted.
The key is to plant as soon as the ground is workable—not frozen or overly soggy. You want the tree in the ground before the intense summer heat arrives in July.
Spring advantages are:
- Full growing season ahead for the tree.
- Easier access to nurseries with their fullest stock.
- Ability to correct any planting issues you notice during the summer.
Months to Avoid for Planting
Summer (July-August) is the most stressful time to plant. High temperatures, intense sun, and dry winds force the tree to try and establish roots while losing massive amounts of water through its leaves. Survival requires relentless, perfect watering.
Winter is simply not feasible because the ground is frozen. You cannot properly plant a tree in frozen soil, and the roots will not grow.
High Altitude Considerations
If you live above 7,000 feet, your planting windows shrink. Spring comes later, and fall frost arrives earlier. Aim for late May to early June for spring planting, and early to mid-September for fall planting. Always choose species specifically rated for your hardiness zone.
Step-by-Step Guide to Planting Your Tree
Once you’ve chosen your time, doing the job right is just as important. Follow these steps for a healthy tree.
1. Choose the Right Tree
Select a species native or well-adapted to Colorado. Think about drought tolerance, mature size, and purpose (shade, privacy, fruit). Your local county extension office is a fantastic resource for recommendations.
2. Dig the Perfect Hole
This is where many gardeners go wrong. The hole should be two to three times wider than the root ball. This loosens the soil for roots to expand easily. However, the depth should be only as deep as the root ball itself.
Planting too deep is a major cause of tree failure. The root flare (where the trunk widens at the base) should be visible above the final soil line.
3. Handle and Place the Tree
Always lift the tree by the root ball, not the trunk. If it’s in a container, gently loosen any circling roots. For balled-and-burlapped trees, remove any wire basket and synthetic burlap after placing it in the hole. Natural burlap can be left in the hole.
Center the tree in the hole and ensure it’s standing straight.
4. Backfill and Water
Backfill the hole with the native soil you removed. Do not amend it with rich compost or potting mix, as this can discourage roots from venturing into the surrounding native soil. Water thoroughly as you backfill to eliminate air pockets.
Create a shallow berm of soil around the edge of the planting hole to form a water basin.
5. Mulch and Aftercare
Apply 3-4 inches of wood chip mulch over the root zone. Keep the mulch a few inches away from the trunk itself to prevent rot. This conserves moisture and regulates soil temperature.
Your most critical job for the first few years is consistent, deep watering. A slow trickle from a hose for 30-60 minutes once or twice a week is better than a daily sprinkle.
Common Mistakes to Avoid
Even with good timing, errors in planting can set your tree back. Watch out for these pitfalls:
- Planting Too Deep: This suffocates roots and leads to trunk decay. Always find the root flare.
- Over-amending the Soil: Creates a “pot effect” where roots won’t leave the comfortable hole.
- Staking Unnecessarily: Most young trees don’t need staking. If you must stake for wind, use wide, flexible ties and remove them after one year.
- Underwatering or Overwatering: Check soil moisture with your finger. It should be moist, not soggy or dusty dry, several inches down.
- Ignoring the Seasons: Trying to plant in July because a nursery has a sale is a recipe for extra work and potential loss.
FAQs: Planting Trees in Colorado
What is the best month to plant trees in Colorado?
For fall planting, aim for September to early October. For spring planting, target late April through May. Adjust slightly earlier for fall and later for spring if you’re at a high elevation.
Can I plant trees in Colorado in the summer?
It’s not recommended. The heat and dry air put immense stress on a new tree. If you must, be prepared for a very strict, daily watering regimen and use plenty of mulch to conserve moisture. Container trees might handle it slightly better than balled-and-burlapped ones.
What are the best trees to plant in Colorado?
Focus on drought-tolerant, hardy species. Excellent choices include Colorado Blue Spruce, Ponderosa Pine, Bur Oak, Hackberry, Hot Wings Maple, and species of Hawthorn and Crabapple. Always check the USDA hardiness zone for your specific location.
How often should I water a newly planted tree in Colorado?
Water deeply 1-2 times per week during the first growing season. In hot, dry, or windy periods, you may need to water more often. The goal is to keep the root ball area consistently moist but not waterlogged. In winter, water during warm, dry spells when the ground isn’t frozen.
Is it to late to plant a tree in October?
Early to mid-October is usually fine, especially for deciduous trees. The key is to get it in the ground at least 4-6 weeks before the ground freezes hard. This gives some time for root establishment. For evergreens, aim to finish by early October, as they lose moisture through their needles all winter.
Choosing the right time to plant is the first and most important gift you can give your new tree. By opting for the calm conditions of fall or the fresh start of spring, you align with Colorado’s natural rhythms. Pair that timing with a proper planting technique—a wide, shallow hole, careful handling, and dedicated aftercare—and you’ll greatly increase your chances of success. Your careful planning now will be rewarded with a healthy, beautiful tree that provides shade, beauty, and value for decades to come. Remember, the effort you put in during the first few years sets the foundation for it’s entire life.