Example 35 : NCDOT Roadside Vegetation Management Guidelines in Marked Areas

• No mowing April 1-November 15.
• No herbicides, no fertilizers. ( Exceptions can be made for herbicides under special circumstances, discussed below. )
• Mowing from November 16-March 31 is allowed and, in most cases ( *see exception below ) , should be done at least every other year. Winter mowing every year is acceptable. If regular contract mowers are unable to mow the sites under this time frame, NCDOT mowers may be used during the winter.
• Mowing should not be conducted when the soil is wet, as compaction and rutting will occur.
• In some instances, rare plants may be growing right along the edge of the road. Ideally, the plants should be protected if at all possible in this situation, but if NCDOT division staff determine that the road shoulder should be mowed during the growing season for safety or visibility, then the shoulder may be mowed accordingly. If possible, an NCDOT biologist can visit the site and mark where individual plants are, so they can be avoided.
• NCDOT mowing contracts are under modification to ensure that contractors are responsible for finding out if any endangered plants are within the areas they will be working, and for avoiding injury to the plants. The County Mowing Inspector or the Division Roadside Environmental Engineer should review the No Mow policy with each county maintenance office and mowing contractor prior to any mowing activities on roads with rare plant populations.
• The standard mowing height is usually four inches; ideally, the mower should be set at a level to avoid scalping the ground and damaging rare plants.
• Clippings from winter mowing should be left on site so any rare plant seeds produced will have the opportunity to germinate within the population. An exception can be made if only weeds are reproducing.
• Prior to entering the site, mowers and equipment should be cleaned off, removing any accumulated vegetative debris that contains weed seeds.
• Rare plants along roadsides often extend into utility line ROWs. Utilities managing plant growth in DOT ROWs must be told that herbicide use on DOT ROW is unlawful without a permit. Utilities conducting plant management adjacent to DOT ROWs should be notified when rare plants are present.

* Mowing Exception

There is an exception to winter mowing for Virginia spiraea. This shrub is found along streams, rivers and roadsides in the mountains. Because it is a woody shrub it should never be mowed, regardless of the time of year. Trimming or selective thinning of other woody vegetation that compete with this species may be recommended for management.

Signs/Stakes
When rare plants are discovered on NCDOT's ROW, the population should be marked with ‘Do Not Mow' signs. These signs should be large enough to be easily noticed by roadside mowers. A variety of signs have already been placed along roadside populations; most simply state, ‘Do Not Mow' while others include dates for the no mow period ( April 1 - November 15 ) , or add ‘Do Not Spray.' To ensure that signs are readily understood by a variety of workers, signs with universal symbols for ‘Do Not Mow' and ‘Do Not Spray' are under review for future use.

Do Not Mow signs should be positioned at both ends of a population, facing so mowers will see the signs as they approach the No Mow area. Where rare plants occur along a significant stretch of roadway it is suggested that double sided Do Not Mow signs be placed periodically along the population - two Do Not Mow signs placed back to back on a single post. The reasoning for this is that if a sign at one end of the population disappears, the mower will encounter another Do Not Mow sign before the entire population is mowed. Maintaining the signs and seeing that they are visible and in good condition is critical in order to protect these populations. Damaged or missing signs should be replaced as soon as possible, especially during the growing season. If possible, signs should be placed at a low enough level for the mower operator to see.

White-topped wooden stakes can also be useful in alerting mower operators that the site is designated as a No Mow area. These should be used in addition to ( not instead of ) Do Not Mow signs. The wooden stakes are approximately 40 inches long with the top six inches painted white, the same stakes used to delineate mowing patterns and areas that are off limits to mowers. Stakes should be placed at regular intervals along the entire edge of the roadway side of the population.

Encroachments/Maintenance
Division environmental officers, district offices and maintenance units should make sure rare plant sites are taken into consideration for proposed ROW encroachments and maintenance work. ROW encroachments such as driveways, utility work, minor widenings, installation of utility lines and pipes for driveways have the potential to damage rare plant populations. All ROW access requests and driveway access applications in areas where rare species are known to occur should be reviewed to ensure there will be no impacts. If impacts to rare plants are likely to occur, efforts should be made to avoid or minimize damage. District offices should maintain secondary road files with a notation to remind them that the road has a protected species.

Roadside maintenance activities, such as grading and ditch maintenance can also harm rare plants. As above, if impacts to rare plants are likely to occur, efforts should be made to avoid or minimize damage. Heavy equipment should be kept out of rare plant areas during the No Mow period. Employees working in the area should be shown the rare plant so they can avoid damaging them.

Herbicide Use
To reduce competition from invasive weeds, herbicides should only be used when mechanical removal is not an option. Herbicides can be used near rare plant populations when specifically prescribed by someone familiar with the biology of the rare plant. Two main herbicides have been recommended for use on roadside rare plant populations. These herbicides have been tried in a variety of situations by NCDOT and are believed to be most suitable for managing these sites, glyphosate triclopyr for woody vegetation. All herbicide applications for roadside rare plant sites should be conducted by a Licensed Pesticide Applicator.