ISA Certified Arborist RM-8846A
Tree Planting and Species Selection in Boulder, Colorado
Thorough, well selected planting. Nursery trees are expensive, and this is not the place to cut corners.
Short answer
The two decisions that determine whether a newly planted tree thrives are species selection for the actual site and correct planting depth, and both are made before the tree ever goes in the ground.
Trees mature, get diseased, and sometimes have to come out. Plenty of properties also simply have no established trees to begin with. Installing trees well requires education and experience if expensive nursery stock is going to succeed, and it is crucial not to cut corners on a planting job.
Species selection is where most planting failures are actually decided. A tree has to suit its site: available root volume, sun exposure, irrigation, soil conditions, mature size against the space it has, and susceptibility to the pests already present in this area. Boulder's experience with ash is the clearest possible argument for diversity. When a neighborhood plants one species heavily and a pest arrives that targets it, the whole canopy goes at once. The City's own replacement approach now emphasizes a diverse mix of large-maturing, non-ash species for exactly that reason.
Installation is the other half. Planting depth, handling the root ball and correcting circling roots, the size and preparation of the hole, backfill, mulch kept off the trunk flare, and establishment watering all decide whether the tree spends its first three years growing or struggling.
What does this service include?
- Species selection Matching species to site conditions, mature size, and local pest pressure.
- Diversity planning Avoiding monoculture so one pest cannot take the whole property.
- Correct installation Proper depth, root ball handling, backfill, and mulching.
- Establishment guidance What the tree needs through its first seasons to actually take.
Where is this service available?
Tree Planting and Species Selection is available across Boulder County and Broomfield.
Answers
Planting questions Boulder homeowners ask
What is the best time to plant a tree in Boulder?
Spring and fall are both workable in Boulder, and each has a tradeoff. Spring planting gives the tree a full growing season to establish roots before winter, but it also means facing summer heat while the root system is still small. Fall planting takes advantage of cooler weather and warm soil for root growth, but the tree needs enough time before hard freeze. Either way, consistent establishment watering matters more than the exact planting month.
What should I plant instead of an ash tree?
Something other than another ash, and ideally not whatever your neighbors just planted either. Boulder's ash losses are a direct lesson in what happens when a single genus dominates a neighborhood canopy. The City's approach when removing infested public ash is to replace with a diverse mix of large-maturing, non-ash species. The right specific choice for your yard depends on your space, soil, exposure, and irrigation, which is what the site visit sorts out.
How deep should a tree be planted?
The trunk flare, where the trunk widens into the roots, should be visible at or slightly above the finished grade. Planting too deep is one of the most common causes of slow decline in landscape trees, and the damage takes years to show up, by which point the cause is easy to miss. Nursery stock frequently arrives with the flare already buried in the container, so it has to be located rather than assumed.
How much water does a newly planted tree need?
More than most people expect, for longer than most people expect, and delivered slowly. A new tree needs deep, infrequent watering that reaches the whole root ball rather than brief surface sprinkling, and it needs that support through at least the first two to three growing seasons. In Boulder's dry winters, occasional winter watering during warm dry stretches also matters for young trees.
Boulder County
Call for a site visit today
Early site visits and preventative maintenance catch conditions while they are still fixable. Talk to an ISA Certified Arborist about what your trees actually need.
Monday to Friday, 8am to 8pm. Closed Saturday and Sunday. All site visits include a 30 minute arrival window.
Kryn Dykema · RM-8846A