Frequently Asked Questions (F.A.Q.'s)

1. What is a street tree and who maintains them?
2. What type of maintenance is done?
3. Why was my street tree removed?
4. Will my street tree be replanted?
5. What are those green bags on the newly planted trees?
6. My street tree is leaning.  What can be done?
7. Why and how should I mulch the tree-lawn tree?

1. What is a street tree and who maintains them?

Street trees are located in the City’s right-of-ways (typically the area between the sidewalk and the curb) and are maintained by the City’s Parks & Recreation Department, under the supervision of the City Arborist.

2. What type of maintenance is done?

The main tasks of Aurora’s Street Tree Program include PLANTING, PRUNING, and REMOVAL of street trees.  Additional cultural practices such as WATERING, STAKING and PEST MANAGEMENT are also the responsibility of the City.  The residents are encouraged to properly mulch the street trees near their property.

Q.  My street tree looked fine.  Why was it pruned?
The City prunes newly planted and established street trees for a number of reasons.  The main objectives of the pruning cuts are to:
1. Correct structural defects that will be a problem later and remove dead and diseased wood from the plant
2. Encourage a central trunk to develop, thus reducing the length of competing trunks or branches which can lead to structural weaknesses
3. Clear low-hanging limbs over sidewalks for safe pedestrian movement and over streets for vehicular clearance
4. Ensure maximum air and sunlight reach all parts of the tree
5. Establish good structure of primary scaffold (lateral) branches.  The scaffold branches provide the framework of the mature tree. 

Proper pruning a few years after planting is essential in developing a tree with a strong structure and desirable form.  Properly pruned young trees will develop a strong structure that requires less corrective pruning as they mature.  The pruning cuts may look dramatic, but keep in mind these are STREET trees and need to be pruned so they remain safe as they mature.  Tree pruning can be done anytime during the year, but the best time is during the dormant season, therefore the City conducts the majority of pruning during the winter.  Our goal is to prune each street tree once every five to seven years.  The tree crew typically prunes the trees on a given street and leaves the branches in the tree lawn.  At the end of the work day - or if they are moving to a new location at that time, they will return to chip the brush.   This is done to minimize the disturbances to the homeowners (as the chipper is loud).  A Certified Arborist is on site during pruning at all times. 

3. Why was my street tree removed?

Every year, neighborhoods are surveyed for dead, dying, diseased or damaged street trees.  These trees are put on a removal list and removed in late summer by our Parks & Recreation Dept.  The stumps are ground and the area is leveled and reseeded.  Areas where trees are removed are then noted for tree planting in the following planting season. 

4. Will my street tree be replanted?

Yes. New trees are planted the season following removal at no cost to the resident.  Fall (Sept. – Nov.) is the preferred time for new tree planting, followed by late winter or early spring (March – April).  Species are chosen by the Arborist based on the available growing space, overhead utilities, and current diversity planning.

5. What are those green bags on the newly planted trees?

Newly planted trees are under severe water stress right after transplanting, and they will remain under water stress for the first several years after planting.  The City installs Treegator bags on all newly planted trees.  These bags deliver a high volume of water (up to 20 gallons!) directly to the root system of a newly planted tree and slowly release this water over a 6 to 10 hour period.  They are typically refilled once a week, thus reducing premature tree death and increasing establishment time. 

6. My street tree is leaning.  What can be done?

We encourage you to contact the City Arborist and request the tree be staked – please do not do it yourself.  We use special tree staking materials that won’t injure the tree. 

7. Why and how should I mulch the tree-lawn tree?

PLEASE DO NOT OVER-MULCH!  It is harmful to the tree.  A thin layer of mulch should be placed around the base of the street tree to prevent damage from lawnmowers and string-trimmers, and to suppress weeds & control soil temperatures. Mulch only needs to be applied and maintained at a two- (2) inch depth at the tree’s dripline. As the original mulch decomposes, it should be stirred, turned over or broken up to improve aeration and water diffusion capability. When mulching, remember:
- Do not apply more than 2-3 inches of mulch
- Do not pile mulch against the trunk of a tree
- Do not let matted and compressed mulch build up year after year