Trees to Avoid

These are either trees on the Colorado Noxious Weed List or are not recommended for our area.

Colorado Department of Agriculture: List B species. The goal is to stop the spread of the indicated species.

	Common Name	Scientific Name	Comments
	Russian Olive	elaeagnus angustifolia	Unfortunately, this tree out-competes native streamside vegetation and is no longer allowed to be sold in Colorado.
	Salt Cedar	tamarix chinensis, T. Parviflors, and T. ramosissima

Department of Agriculture: Plant Industry Division. Prunus species OTHER THAN those listed below are not allowed to be imported into the San Luis Valley. The purpose of this Quarantine is to protect the potato fields in Alamosa, Conejos, Costilla, Rio Grande and Saguache counties against the over wintering host of the primary aphid vector of certain viral diseases that affect potatoes. To see the latest data, go to the CO State webpage tinyurl.com/d8pc3xw and click on the "1.00 Quarantine" link.

	The following are the ONLY ALLOWED PRUNUS species
	Common Name	Scientific Name
	Western Sand Cherry	prunus besseyi
	Purple Leaf Sand Cherry	prunus cistena
	Flowering Almond	prunus galndulosa
	Amur Chokecherry	prunus maackii
	Nanking Cherry	prunus tomentosa
	Flowering Almond	prunus triloba
	Chokecherry	prunus virginiana

Not oulawed, but discouraged.

	Common Name	Scientific Name	Comments
	Chinese (Siberian) Elm	ulmus pumila	These prolific seeders are responsible for the gutters full of seeds in the spring. Weedy volunteers sprout throughout Colorado. They are short-lived trees that shed limbs easily in snow or wind storms and are susceptible to elm leaf beetle. Consider the American Elm, ulmus americana, as an alternative.