Class I Trees

class1.jpgClass I trees are the smallest growing trees in Boise.  They are not commonly used as street trees because they have short, wide canopies that often interfere with street and sidewalk traffic.  They also provide very little environmental benefit (shade, air cleaning, energy savings) relative to Class II and Class III trees.  Many do, however, provide a lot of aesthetic benefit due to their flowers.  For detailed descriptions about individual species, click the links below, email the City Forester or ask a nursery professional.

If you are having a street tree planted, check the planting work order you received, if "Class I" is indicated, you should choose from the list of Class I trees provided with the work order.  If you would like a different Class I species than those available from our nursery, check the "Request Planting Permit" box and write the desired tree species down.  Please don't purchase the tree until Community Forestry has approved the permit. 

Here are some Class I species that may be appropriate:


Most Class I tree can grow to a height of 20-30 feet, with a similar crown spread.  A few columnar varieties exist.

Fall colors vary between species (and in species).  Check the descriptions or email the City Forester for details.

Class I trees are allowed ONLY where a Class II or Class III species will not fit due to overhead wires or other space restrictions.

Many of them flower abundantly (depending on species), and may or may not set fruit. On some, fruit remains on the tree through winter, and can attract birds and other wildlife.

Require a minimum planter strip width of at least 10 feet, unless otherwise approved by Community Forestry.

Every species grows best under certain conditions, usually relating to soil requirements and exposure to sunlight.  Check your planting site and tree details before deciding.

Some species are more drought tolerant than others, check tree details and know how much you do or can water before deciding. No tree is drought proof, all of these trees need regular watering throughout their lives to remain healthy.