This winter, forestry crews have been busy with a wide variety of work. Much of our large tree pruning is accomplished during the winter months to prevent damage to turf in our parks. Crews have been pruning the mature cottonwoods in Jaycee Park to remove dead, broken, and weakly attached branches. Trees such as these, that are in the later stages of life, need more frequent pruning to remove large dead limbs before they fail and threaten public safety.
Crews have also been removing Colorado Blue spruce trees which have been infested with Spruce Ips beetle, which are also called engraver beetles. Older spruce growing in non-irrigated areas appear to be the most vulnerable to infestation. Forestry is making plans to protect high value vulnerable spruce trees by spraying them with insecticide this spring. Forestry is also recommending to homeowners that they hire a licensed arborist to spray their vulnerable spruce this spring. More information on Spruce Ips can be found here.
Staff will also be mulching around newly-planted trees. Tree watering will be conducted on conifers in non-irrigated areas and newly planted trees as well. Mulching and watering is critical for the survival of newly-planted trees and trees that are in dryland areas. Mulch helps to hold soil moisture, moderate soil temperatures, improve soil conditions, and reduce competition with grass and weeds. Winter watering is critical to the establishment of young trees, especially conifers that actively transpire in the winter.
Crews recently completed the removal of Russian olive trees along Dry Creek, adjacent to the greenway between Ridge Rd. and College Ave. Russian olive is a non-native, noxious weed that chokes-out native vegetation, increases fire danger and restricts the water flow of creeks and rivers. Crews cut down the trees, chipped-up the brush, and applied herbicide to the stumps to kill the root system. These areas will need to be monitored in the future and any re-sprouting will be treated with herbicide. Future Russian olive removal projects are being planned for additional riparian areas within the city.