Tree Planting & Replacement

Choosing the right tree

The best time to choose a tree is before you dig. Think about how big it will be in 30 years, not how big it is at the nursery. A shade tree planted under power lines or a few feet from the house will need heavy pruning for its whole life, or removal later. Our arborist looks at the spot, the soil, the sun and the space above and below ground, and suggests species that suit it. Planting a mix of species is wise, too. Neighborhoods that planted mostly ash, like many around Denver, are losing large numbers of trees to emerald ash borer at once.

Replacing an ash or a lost tree

Many of our planting jobs replace an ash that has come down, or a tree lost to a storm. We usually plant the new tree a few feet away from the old stump, where the soil has not been filled with grinding chips and old roots. In Denver, planting in the strip between the sidewalk and the street needs a free permit from the Office of the City Forester, and the species must come from the city's approved street tree list unless the forester agrees otherwise. Other cities have their own lists and rules, and we check them before we order the tree.

How we plant

Before any digging, we place a Colorado 811 locate request, and we ask you to mark private lines such as sprinklers. The hole is dug wide and shallow: two to three times the width of the root ball, and no deeper than the root ball itself, so the root flare where the trunk widens sits at or slightly above the soil line. Trees planted too deep are a common cause of slow decline years later. We remove wire baskets, twine and burlap from the top of the root ball, backfill with the native soil and water it in. Mulch goes on two to four inches deep, kept a few inches away from the trunk. We only stake trees that need it, and we come back to remove the stakes.

Watering the first years

A new tree needs regular deep watering while its roots grow out into the soil, which takes a few years. Lawn sprinklers alone rarely give it enough. In dry winters, Colorado State University Extension advises watering trees during dry spells when the air is above 40 degrees, the ground is not frozen and there is no snow cover, ideally at midday so the water soaks in before night. We leave you a simple watering schedule for your tree.

When to plant

Spring and fall are the best times to plant in Denver. The soil is workable, temperatures are mild and the tree has time to grow roots before summer heat or winter cold. We plant container and balled-and-burlapped trees, from small ornamentals to larger shade trees set with a small machine.