City of Alexandria 2019 Landscape Guidelines FAQs

Page updated on Sep 5, 2019 at 10:14 AM


1. What is the preferred way to communicate the existing conditions information?

The existing conditions plan information may be combined with the Tree & Vegetation Survey Plan OR provided as a separate plan.

2. I am preparing a Grading Plan application where only one new tree is needed to satisfy the crown coverage requirements. Does the proposed landscape plan still need to be prepared by a licensed Landscape Architect?


3. Which professional is responsible for preparation and certification of the Invasive Species Removal Management Plan?

An Arborist professionally certified by the International Society of Arboriculture, or professionally registered with the American Society for Consulting Arborists, OR a Certified Ecologist must prepare the Invasive Species Removal and Management Plan.

4. If the scope of work includes only a portion of a site and not the entire site, does the tree inventory have to include trees located within the entire site and 15-feet from the property line?

In cases where the scope includes only a portion of the property: 1) For the purpose of determining the location of tree protection fencing, the tree inventory should account for all existing trees located inside, or within 15-feet, of the Limits of Disturbance (LOD). 2) For purposes of calculating crown coverage, the tree inventory should account for all existing trees to remain and to be removed on the site.

5. Does the extent of the critical root zone for individual trees and/or groups of trees need to be shown for trees that are to be removed?


6. Does the existing grade elevation at the base of the tree trunk and at the edge of the critical root zone of the tree need to be surveyed?

The existing grade elevation at the base of the trunk and at the edge of the critical root zone may be interpolated for existing trees to be saved (information is not necessary for existing trees to be removed).

7. The standard reads, "Survey information is to include individual plants or groups of listed invasive species as listed within Chapter 6." What if there are no existing invasive species on-site?

If no existing invasive species are identified, provide a statement on the Tree and Vegetation Survey sheet that indicates no invasive species exist on the site at the time the survey was completed (list the date; Month Day, 20XX).

8. The standard reads, "Where it is impractical to provide a protection zone at the limits of the CRZ and the project arborist determines that the tree is likely to survive construction activity and disturbance, the tree protection zone shall be no less than 8 feet from the vegetation to be protected." Does this 8 foot standard apply to street trees to be saved?

Tree protection fencing for street trees to be saved should be maximized to the extent practical without precluding use of the adjacent sidewalk and/or street. At a minimum, tree protection fencing shall be provided at the limits of the existing tree well for street trees to be saved.

9. What is the procedure for notifying the neighboring property owner when the neighboring property is owned of the City?

When development proposes disturbance within the CRZ of existing vegetation that is owned by the City, the P&Z plan reviewer will notify the City Arborist. Additional coordination, including discussion, site visits, and/or requests for additional information, between the applicant, the P&Z plan reviewer and the City Arborist may be necessary prior to approval of the plans.

10. Is the canopy coverage for existing trees based on the City-assigned crown coverage allowance for the tree, or calculated per the surveyed crown coverage area?

The surveyed crown cover area should be used for the purposes of calculating the crown coverage of existing trees.

11. Can the crown cover of existing, invasive trees count toward the project's crown cover requirement?

No. Invasive species should be removed.

12. The standard reads, "Trees and shrubs used solely within stormwater BMP facilities are not required to meet the diversity standards of Chapter 3. However, BMP plant material should strive to meet the standards to the maximum extent practical." Does this exclusion apply to plants proposed in an RPA?

No. Plant material proposed within an RPA must meet the diversity standards of Chapter 3.

13. The standard reads, "One street tree is required for every thirty (30) feet of lot frontage along the public right of way…" Is this standard cumulative of the total lot frontage, or per frontage?

One street tree is required for every cumulative 30 feet of lot frontage. However, street trees shall be spaced a minimum of every twenty-five (25) linear feet and a maximum of every thirty (30) linear feet (specified on-center, O.C.).

14. Do the at-grade soil volume and depth standards apply to BMP tree wells?

Refer to the City's Green Street BMP Design Guidelines for minimum soil volume and depth requirements of BMP tree wells.

15. My project was submitted/approved by City Council prior to adoption of the 2019 Landscape Guidelines and is currently in Final Site Plan review. Can I apply the new 2019 crown cover and soil volume/depth standards for trees on structure?

Yes, only if the project complies with the entirety of the 2019 Landscape Guidelines. Applicants may not mix and match standards from the 2007 Landscape Guidelines and the 2019 Landscape Guidelines on one project.

16. Is a soil sample test report that documents the existing soil pH really required at Completeness?

Since trees, shrubs, ground covers and perennials are specified at the Completeness stage, the intent of the soil sample test is to verify that the plants specified are appropriate for the existing soil pH. For projects where the soil is imported and in special circumstances, such as highly urban sites where a soil sample is inaccessible, staff will include a recommended condition of approval in the DSP/DSUP that requires submission of a soil sample test documenting the pH prior to the request for a Certificate of Occupancy.

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