Sec. 9.2. Landscape Design

9.2.1. Landscape Manual

The Landscape Manual for Durham, North Carolina, also referred to as the Landscape Manual shall provide the following:

A. A list of species that shall be used within the City and County of Durham, including appropriate applications and specifications, to satisfy the requirements of this Article for site plansClosed An accurately scaled development plan that shows existing conditions on a site as well as depicting details of proposed development. and platsClosed A map, chart or plan of a tract or parcel of land which is to be or which has been, subdivided..

B. Diagrams depicting required planting methods that shall be included, as applicable, on site plansClosed An accurately scaled development plan that shows existing conditions on a site as well as depicting details of proposed development. and platsClosed A map, chart or plan of a tract or parcel of land which is to be or which has been, subdivided..

C. Diagrams depicting required tree protection fencing specifications that shall be included, as applicable, on site plansClosed An accurately scaled development plan that shows existing conditions on a site as well as depicting details of proposed development. and platsClosed A map, chart or plan of a tract or parcel of land which is to be or which has been, subdivided..

D. Diagrams illustrating recommended methods for bufferClosed A portion of property designated to mitigate impacts between land uses or transportation routes, or to protect water features from pollutants. depictions on site plansClosed An accurately scaled development plan that shows existing conditions on a site as well as depicting details of proposed development. and preliminary platsClosed A map indicating the proposed layout of a development and related information that is submitted for preliminary review..

E. Recommended best practices for landscaping methodologies including, but not limited to, “water-wise” approaches to landscape materials and incorporation of Crime Prevention Through Environmental Design (CPTED) principles.

9.2.2. Basic Plant Types

There are five basic plant types referred to in this section, and all shall require the use of locally-adapted plants. They include deciduous canopyClosed A roof-like cover extending over an outdoor area for the purpose of sheltering individuals or equipment from the weather. trees, evergreen canopyClosed A roof-like cover extending over an outdoor area for the purpose of sheltering individuals or equipment from the weather. trees, deciduous understory trees, evergreen understory trees and shrubs, defined as follows:

A. Deciduous Canopy Trees

Large deciduous shade trees with a mature height of 30 feet or greater and a mature spread of 30 feet or greater in the Suburban or Rural tiers or, in the SRP-C District (County Only), Urban, Compact Neighborhood, and Downtown tiers, a mature height of 20 feet or greater.

B. Evergreen Canopy Trees

Trees at least 20 feet tall at maturity that usually have green foliage throughout all seasons of the year.

C. Deciduous Understory Trees

Small deciduous trees or large deciduous shrubs with a mature height of 10 to 30 feet.

D. Evergreen Understory Trees

Trees or large shrubs at least 10 feet tall at maturity that usually have green foliage throughout all seasons of the year.

E. Shrubs (Deciduous and Evergreen)

Prostrate or upright woody plants, either evergreen or deciduous, with a mature height usually less than 10 feet. Evergreen shrubs usually have green foliage throughout all seasons of the year.

9.2.3. Plant Material Requirements

Unless specified elsewhere in this Ordinance, plant material shall meet the minimum requirements listed below. When determining the quantity of plant material required, the quantity shall always be rounded up to the nearest whole number.

A. Plant Materials, General

All plant material shall meet or exceed size and shape relationships specified in the latest edition of The American Standard for Nursery Stock published by the American Association of Nurserymen.

B. Trees

1. Deciduous Canopy Trees

Deciduous canopyClosed A roof-like cover extending over an outdoor area for the purpose of sheltering individuals or equipment from the weather. trees shall have a minimum size of two-inch caliperClosed The diameter of plant material, measured at six inches above grade for calipers of up to four inches, and 12 inches above grade for larger calipers. at time of planting, unless permitted under paragraph 8.3.1E.3.

2. Evergreen Canopy Trees

Evergreen trees shall have a minimum height of eight feet at the time of planting.

3. Deciduous Understory Trees

a. Deciduous understory trees with single stems shall have at a minimum size of one-inch caliperClosed The diameter of plant material, measured at six inches above grade for calipers of up to four inches, and 12 inches above grade for larger calipers. and a minimum height of eight feet at the time of planting.

b. Multi-stemmed deciduous understory trees shall have a minimum height of eight feet at the time of planting.

4. Evergreen Understory Trees

Evergreen understory trees shall have a minimum height of six feet at the time of planting.

5. Tree Spacing

a. CanopyClosed A roof-like cover extending over an outdoor area for the purpose of sheltering individuals or equipment from the weather. trees shall be planted at least 18 feet apart.

b. Deciduous understory trees shall be planted at least 12 feet apart.

c. The spacing between canopyClosed A roof-like cover extending over an outdoor area for the purpose of sheltering individuals or equipment from the weather. and deciduous understory trees shall be at least six feet.

6. Mixing of Tree Species

When more than 10 trees are required to be planted on a site to meet these regulations, a mix of species shall be provided. The following table indicates the maximum percentage of trees of the same genus and species that may be planted.

Total Trees Planted on Site

Minimum Number of Species Required

Maximum Percentage of Any Species

10 trees or less

1

Not applicable

11 to 20 trees

2

70%

21 to 50 trees

3

50%

51 to 100 trees

4

40%

101 to 200 trees

5

30%

201 to 300 trees

6

25%

301 to 500 trees

7

20%

Over 500 trees

8

20%

 

C. Shrubs

1. Deciduous and Evergreen Shrubs

a. All shrubs shall be cold hardy and heat tolerant.

b. Upright shrubs shall be a minimum of 15 inches in height at the time of planting.

c. Shrubs shall not be planted closer than three feet on center. Shrubs shall not be planted closer than three feet to planted trees, nor within six feet of existing protected trees; however, no more than 25% of the tree protection zoneClosed The permeable land area around the base of a tree in which disturbances are prohibited in order to protect the roots of a tree and aid the trees survival. Tree protection zones are measured as the greater of: A.  Six-foot radius around the tree; or B.  One-foot radius for every inch of dbh. of an existing tree may be disturbed with new plantings.

d. When planted as a hedge, the maximum spacing for 24-inch high shrubs shall be 36 inches on center. Spacing for other size shrubs shall as specified within the Landscape Manual pursuant to paragraph 9.2.1, Landscape Manual.

2. Mixing of Shrub Species

When more than 20 shrubs are required to be planted on a site to meet these regulations, a mix of species shall be provided. The following table indicates the maximum percentage of shrubs of the same genus and species that may be planted.

Total Shrubs Planted on Site

Minimum Number of Species Required

Maximum Percentage of Any Species

21 to 100 shrubs

4

30%

101 to 200 shrubs

5

25%

201 to 300 shrubs

6

20%

301 to 400 shrubs

7

20%

401 to 500 shrubs

8

20%

501 to 600 shrubs

9

20%

Over 601 shrubs

10

20%

 

D. Plant Species List

1. A list of plants by type and appropriate location or use to satisfy the requirements under this Article shall be maintained within the Landscape Manual pursuant to paragraph 9.2.1, Landscape Manual.

2. A list of prohibited plants identified as inappropriate for use within Durham City and County shall be maintained within the Landscape Manual. These plants shall not be used to satisfy landscaping requirements, either as existing or proposed plant material.

3. When a species or cultivar is proposed for use but is not listed within the Landscape Manual, a professional urban forester or certified plant professional shall certify that the use of the plant material is appropriate for the intended use and location, and that it does not have invasive tendencies.

9.2.4. Landscape Plans and Surveys

Landscaping plans shall be prepared by certified arborists, landscape architects, or other similarly licensed professionals with a proficiency in preparing landscaping plans. Tree surveys shall be reviewed and signedClosed Any words, lettering, parts of letters, figures, numerals, phrases, sentences, emblems, devices, structures, designs, trade names, or trade marks by which anything is made known such as are used to designate an individual, a firm, an association, a corporation, a profession, a business, or a commodity or products, which are legible from any public street or adjacent property and used to attract attention. This definition includes the structure or the face on which a sign message is displayed. For the purposes of this Ordinance, this definition shall not include "trade dress" i.e.: architectural features identified with a product or business, as a sign. by a certified arborist or forester to confirm the size and species of the trees depicted on the plans.

9.2.5. Installation

A. Easements

1. Trees can be planted in access or utility easementsClosed A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes., including stormwaterClosed The flow of water which results from precipitation and which occurs immediately following rainfall or snowmelt. control measure access and maintenance easementsClosed A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes., provided that they are a species adapted for the nature of the easementClosed A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes..

a. Approval by the entity or Department responsible for the easementClosed A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes. shall be required for the location of the trees proposed for planting.

b. Compliance with additional requirements by the responsible entity or Department shall be required.

2. Shrubs shall be installed at least five feet away from the flow line of a swale.

3. Shrubs can be planted in a public utilityClosed A business or service that provides the public with electricity, gas, water and sewer service, telephone or cable television service. A wireless communication facility, unless regulated as a public utility by State or federal regulations, shall not be considered a public utility. easementClosed A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes. provided they are approved by the utility provider.

4. If the entity responsible for an existing easementClosed A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes. denies the location of landscaping material that is otherwise required by this Article, the required landscaping location can be modified to the minimum extent necessary to avoid conflict with the easementClosed A grant by a property owner for use by the public, a corporation or persons of an area of land for specific purposes..

B. Tree Grates

Tree grates for required trees shall not be permitted in the Rural Tier. When used, such grates shall be sized and maintained to ensure continued health of any required tree and installed so as not to create any pedestrian hazard.

C. Groundcovers and Mulch

1. Groundcovers can be planted around trees, provided they are located outside of the planting hole.

2. Mulch shall be used in all areas where no other ground coverClosed Any natural vegetative growth or other material which renders the soil surface stable against accelerated erosion. or grass is used to avoid bare spots.

D. Certification

Certification by a licensed landscape architect or licensed landscape contractorClosed Individuals or firms engaged in the construction of buildings, either residences or commercial structures, as well as activities such as paving, highway construction, and utility construction. verifying that all plants have been installed per all UDO and Landscape Manual requirements shall be submitted before a Certificate of Compliance will be issued.