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 Acidic

having a pH of less than 7

 Alkaline

having a pH of more than 7

 Alternate

a leaf arrangement that refers to one leaf per node.

 At Risk Firewise

refers to a plant with high flammability.

 Bark

refers to the physical characteristics of the bark which impact fire performance of vegetation.Exfoliating or peeling bark on the trunk or limbs can more easily ignite and increase ignitability and ladder potential.

 Cold Hardiness

the average low temperatures over the past 40 years.

 Columnar

a plant form representative of growth that is much higher than broad.

 Common Names

refer to the commonly accepted names for plants and may vary by region.

 Exposure

refers to the amount of sun a plant receives each day. When a plant is not adapted to its exposure, it is more prone to sunscald, poor growth, poor form, disease, insects, and dieback, all of which can increase its potential to ignite and burn.

 Firewise Principles

Those principles that promote the primary objectives of the Firewise program and are based on standards of the National Fire Protection Association.

 Firewise Ratings

 Firewise Suitability

represents Landscape Zones 1, 2, 3, and 4. Zone 1 cannot be selected because Firewise does not recommend planting closer than 5 feet from the house. Zone 4 cannot be selected because recommendations greater than 100 feet from a structure are not made in this application.

 Flammability

refers to the ability of a plant to ignite and transfer heat and/or flames to surrounding plants or structures

 Foliage Density

provides valuable insight into the fire ignitability of the plant. Foliage density can also become contingent upon the overall mature size of the plant. Less dense foliage tends to have less actual fuel for ignition and less overall mass whereas very dense foliage can burn longer and hotter and increase the ignition of other plants and structures nearby. The combination of both of these—leaf characteristics and the amount of foliage—can greatly affect the fire performance of a particular plant.

 Full Sun

exposure where a plant receives full sun all day.

 Genus

a category of biological classification that ranks between the family and the species and contains related species

 Ground Cover

refers to plants which have a prostrate growth habit and tend to cover large areas of space.

 Heat Tolerance

refers to zones delineated according to the American Horticulture Society in the late 1990s. These are based on the average high temperatures for the number of days over 85 degrees.

 Herbaceous

having little or no woody tissue and persisting for more than one growing season.

 Home Ignition Zone

begins with at least 30 feet of space immediately around the home and extends out as far as 100 to 200 feet depending on the characteristics of the adjacent lands.

 Ignitability

refers time to ignition once exposed to an ignition source such as an ember or flame.

 Ignition

refers to how quickly a plant will catch fire.

 Invasiveness

refers to the ability of a plant to establish and outcompete other plants in an environment. Many exotic plant species have become invasive and negatively impact diversity and natural landscape processes.

 Ladder

refers to the potential of a plant to raise fire from the ground level up and onto a structure.

 Landscape Zone

refers to the list of plants best suited for because they have the form, size, and fire-performance characteristics acceptable for use in Zone 2.

 Landscape Zone 1

is the area within the Home Ignition Zone which extends 5 feet from a structure where it is recommended that no planting occur.

 Landscape Zone 2

is the area within the Home Ignition Zone which extends from 5 to 10 feet from a structure. Firewise adapted vegetation and practices should be used within this zone.

 Landscape Zone 3

is the area within the Home Ignition Zone which extends from 10 to 30 feet from the structure. Firewise practices should be used within this zone minimize the movement of fire.

 Landscape Zone 4

is any area beyond 30 feet and up to 200 feet from the structure. The fire performance plant selector does not make recommendations for planting in this zone.

 Leaf Arrangement

refers to the location of leaf nodes on a stem either opposite or alternate in arrangement.

 Leaf Color

refers to the natural color of the leaf. Leaf color can provide valuable insight into a plant’s health and can be an important indicator of fire performance.

 Leaf Surface

represents characteristics of the leaf surface that range from hairless to very hairy and can impact fire performance.

 Leaf Type

refers to the shape of a leaf which can be simple, compound, a blade or scale-like.

 Leathery

having a thick, dense leaf

 Moderately Firewise

refers to plants that have moderate flammability. Care is needed to keep these plants less flammable. Personal wildfire experience can also be utilized with these species to more strongly rank the species as firewise.

 Needles

refers to leaves of conifers which more readily ignite due to the presence of resins

 Neutral pH

having a pH of 7

 No if Limbed

refers primarily to trees and shrubs that will develop a primary trunk if lower branches are removed resulting in a plant that is less likely to move fire upward and onto a structure

 Number of Trunks

refers to the number of trunks on shrubs or trees.

 Oily Foliage

refers to a leaf type that is covered or impreginated with oils rendering it more likely to ignite..

 Opposite

is a leaf arrangement used in plant identification that means there are two leaves to a node.

 Papery

refers to a leaf that is thin and less dense. Papery foliage more easily ignites when dry.

 Partial Sun

refers to exposure of a plant receiving less than half a day of sun.

 pH

refers to the acidity, alkalinity, or neutrality in the soil. pH influences a plant's ability to utilize essential nutritional elements.

 Plant Form

refers to the manner in which a plant grows

 Poor Drainage

refers to plants adapted to poorly drained soil.

 Prunability

refers to the response of a particular plant to pruning. Some plants do not respond well to severe pruning in a utility right-of-way and will develop water sprouts, suckers, and poor form. Improper pruning may also cause dieback of cut branches or dieback of the entire plant. Improper pruning techniques have a direct correlation to both vitality and debris buildup in the plant, which results in an increase in its potential fuel load and ignitability.

 Resinous Foliage

of conifers is extremely easy to ignite.

 Right-of-Way Use

refers to the proper use of plants in utility rights-of-way, easements, and beneath utility lines. However, in many cases, utility companies would prefer minimal planting within their rights-of-way and beneath electric lines because these plantings may increase their required maintenance costs associated with reliable power transmission. The reality of requiring no planting in utility rights-of-way is unrealistic. As a result, most companies promote the use of smaller, less aggressive, urban-adapted trees.

 Size

refers to the mature size of the plant under normal and acceptable growing conditions.

 Species

is a category of biological classification below the genus or subgenus that comprises closely related species.

 Spreading

refers to a growth pattern in plants that tends to be wider than high.

 Sun to Shade

refers to situations where a plant may receive morning sun to shade, afternoon sun to shade, or vice versa, or can vary anytime from sun to shade during the day.

 Urban Use

refers to the adaptability of vegetation to constraints within the built environment.

 Utility Use

relates to the adaptability of vegetation for use in rights-of-ways and especially under electric wires. Only smaller growing trees should be planted in these areas to assure contact will not be made with live foliage.

 Vase-shaped

refers to an upright spreading growth form of a tree or shrub

 Vigor

refers to active, healthy well balanced growth in a plant.

 Vine

refers to a plant whose stem requires support and which climbs or trails above the ground.

 Waxy Covering

refers to a covering on a leaf. Waxy leaves tend to ignite more easily.

 Well Drained Soil

generally refers to a soil that can absorb one half inch of water per hour.