Trees in Arvada grow under conditions most planting guides are not written for. The air is thin and dry, the sun at this elevation is harsh on thin bark, and the swing between a warm afternoon and a freezing night is severe enough to split trunks on young or recently planted trees. Add a semi-arid climate where irrigation does most of the work, and the result is that a lot of local tree trouble comes down to water, timing and structure rather than disease.
Late winter, while the tree is dormant and before buds break, is the window that suits most species here. The structure is visible without leaves in the way, cuts close over quickly once growth resumes, and the insects that spread certain diseases are not yet active. Some species bleed heavily if cut in early spring, which looks alarming but is rarely fatal. The genuine exceptions to dormant pruning are dead, broken or hazardous limbs, which come off whenever they are found, and storm damage, which cannot wait for a season.
The heavy wet snow that arrives here in spring and autumn falls while trees are still carrying leaves, and that combination brings down more limbs along the Front Range than wind does. Trees with narrow branch unions, co-dominant stems or a heavy one-sided canopy are the ones that fail. Thinning before those seasons reduces the sail area a wet snowfall can load.
Dry winters with little snow cover leave root systems desiccated, and the damage does not show until the following summer, when the tree leafs out weakly or not at all. Watering during warm spells when the ground is not frozen, on a mild day so moisture soaks in before nightfall, prevents a problem that is otherwise diagnosed months too late.
Mushrooms or conks at the base, bark falling away in sheets, a sudden lean with disturbed soil on the opposite side, deep cracks in the trunk, and a canopy that thins from the top down are all worth looking at rather than waiting out. Ash trees deserve particular attention, since emerald ash borer has been confirmed in Colorado and early infestation is easy to miss.
Grinding removes the stump below grade so the area can be replanted or turfed, and it is faster and less disruptive than full extraction because the root plate stays in place. Where a new tree is going into the same spot, more of the root mass usually needs to come out.