Overview and schedule of general maintenance activities for tree trenches and tree boxes

Overview and schedule of general maintenance activities for tree trenches and tree boxes
First Year of Operation
Activity	Frequency	Time period	Level of effort	O&M benefit^a
Check that there is no ponding within the box or trench.	At least twice after storm events > 0.5 inches	Within the first 6 months	1-2 hours	1,5
Check for evidence of clogging in the media.	At least twice after storm events > 0.5 inches	Within the first 6 months	1-2 hours	1
Supplemental watering, during drier periods, particularly if keeping stormwater offline trees are established.	1/week initially	During first two months of the growing season	1-2 hours	2,3,4,5,6
	As needed	First growing season	1-2 hours	2,3,4,5,6
Remove any weeds present	As needed	First growing season	1-2 hours	2,3,4,5,6
Remove any trash or debris	As needed	First growing season	1-2 hours	1,2,3,4,5,6
Add mulch if layer is less than 3 inches^b	As needed	First growing season	1-2 hours	4,5
Clean root collar	Annually	During growing season	1-2 hours	1
Remove stakes	As needed	End of growing season	1-2 hours	5
Inspect tree health	Biannually and after large storms	First growing season	1-2 hours	1,2,5,6

After First Year of Operation
Activity	Frequency	Time period	Level of effort	O&M benefit^a
Check that there is no ponding within the box or trench.	Biannually	Any time when ground is not frozen	1-2 hours	1,5
Check for evidence of clogging	Biannually	In spring and fall	1-2	1
Supplemental watering during drier periods	As needed or when soil is dry 3 inches below the surface	Dry periods until roots are established	1-2 hours	2,3,4,5,6
Remove any weeds present	As needed	During growing season	1-2 hours	2,3,4,5,6
Remove any trash or debris	As needed	Any time	1-2 hours	1,2,3,4,5,6
Add mulch if layer is less than 3 inches	Annually	During growing season	1-2 hours	4,5
Remove stakes (if still present)	Once	End of second growing season	1-2 hours	5
Prune excess growth	Once in year 2 or 3, Every three years between years 4-10, Every five years as needed after 10 years	End of winter or early spring	1-2 hours	2,5,6
Inspect tree health and safety	Biannually and after large storms	During growing season	1-2 hours	1,2,5,6

After 5+ Years of Operation (non-routine maintenance)
Activity	Frequency	Time period	Level of effort	O&M benefit^a
After long term operation of the practice, some occasional and infrequent maintenance activities might be required, such as tree or media replacement.	As needed	As needed	Could be significant depending on the activity	1,2,3,4,5,6
^aKey to Maintenance Benefits: 1. Proper stormwater flow and infiltration 2. Creation and maintenance of wildlife habitat 3. Creation and maintenance of pollinator habitat 4. Nutrient cycling and storage 5. Aesthetics and public enjoyment 6. Carbon sequestration Note that many practitioners are minimizing the use of mulch or using alternatives to mulch to control weeds. Using mulch can cause clogging of inlet, outlet, and bypass pipes, and can introduce invasive species such as jump worms. Alternatives to mulch include ground vegetation such as clover or sedges or arranging plantings in more dense configurations so as to minimize use of mulch.
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