La. Admin. Code tit. 70 § I-311
Current through Register Vol. 50, No. 11, November 20, 2024
Section I-311 - WildflowersA. General 1. Louisiana and the Department of Transportation and Development are embarking on a statewide plan for the planting and preservation of wildflowers along its rights-of-way. The Department of Transportation and Development and Louisiana Project Wildflower are working very closely evaluating equipment, planting methods and herbicide operations to produce maximum stands of wildflowers.2. It shall be the policy of the department to encourage the growth, planting and preservation of wildflowers in order to provide a natural setting for the traveling public. Mowing and spraying operations shall be coordinated and timed to enhance the wildflower population and provide a naturally appealing roadside appearance.B. Establishment of Wildflower Areas 1. One of the best methods of establishing wildflower areas is by observing and documenting native stands in order that they may be preserved for future generations. To this end, a form has been developed in order for the traveling public to report and document any sightings of wildflowers along the state's rights-of-way. These forms will be available in all district offices of the Department of Transportation and Development and Louisiana Project Wildflower will distribute these forms at all of their meetings.2. Another method would be to stockpile topsoil which has wildflower seed present and transport this soil to desired locations. This method allows some seed to remain in place and allows the establishment of new stands in other locations.3. Other means of collecting wildflower seed is by cutting the wildflowers with a sickle mower and gathering the cut flowers laden with seed. These cuttings can then be transported to another location and spread, thus establishing a new stand of wildflowers.4. The method which is being practiced more frequently is by direct planting. Wildflower seeds are being commercially grown and although expensive, they are producing desired results with less effort than other means.5. Commercial seed suppliers are able to supply individuals with a mix of several species of seeds or in lots of individual species of seed. Once a selection of types of seed has been determined, it is necessary to establish a planting rate based on the amount of Pure Live Seed (PLS). PLS is the amount of purity multiplied by the percent of germination. The PLS in a lot of seed can be obtained from the supplier. In wildflower planting a rate of 36 to 45 seeds per square yard is normally adequate. Areas that are to be experienced by pedestrians should be planted at a rate possibly 1.5 greater than this. These rates are broad guidelines and should be adjusted to obtain the desired effect. A partial listing of commercial wildflower seed sources is contained herein for informational purposes.6. Planting times will vary according to the conditions the seeds are being planted. Generally wildflower seeds are planted between late fall and spring, although some can be planted during the summer providing supplemental irrigations is available.7. There is a certain amount of risk associated with planting the seed in late fall. Rain and warm temperatures could cause the seed to germinate prematurely and be killed by a freeze.8. Site selection is one of the most important factors in establishing new stands of wildflowers. Be sure to establish the site conditions required to grow certain species. Some may require full sun, others partial shade, still others may require constantly moist soil and others well drained soil. Sites that are relatively weed free with existing stands of shorter grass works best. On sloping sites consideration should be given to seeding grass along with the wildflowers. In some cases, it may be necessary to use a fiber mat to hold the soil and seed in place until germination.9. Wildflowers have a wide tolerance of soils and PH (Acid/Alkaline) conditions. Wildflowers do best in soils of low fertility. High nitrogen soils only encourage the growth of weeds thus causing competition for growth and slowing of the wildflowers. If a site is void of nutrients, it may be wise to consider the use of a low nitrogen fertilizer such as 5-10-10.10. Soil preparation is not absolutely necessary since most wildflower seeds can be broadcast over undisturbed ground. If this method is followed, you can expect some delay in germination and some of the seed can be displaced by the elements or eaten by birds and rodents. The key element in planting wildflower seeds is to have good soil to seed contact.11. One method of insuring soil, seed contact is by mowing the area to be planted as close as possible and remove grass clippings and weeds by raking the entire area. Then lightly till the site with a flail motor, roto tiller, harrow, discs or a weighted section of chain link fence pulled behind a tractor. It is important not to till the ground too deep since this will encourage the growth of any weed seed which may be present in the topsoil. A maximum depth of 1/2 inch is sufficient. In areas which have a strong weed population, it is necessary to treat the unwanted vegetation with a herbicide and removing the dead plants prior to disturbing the ground surface.12. The size of the area to be seeded will determine the type of equipment best suited. On small areas hand sowing or a small mechanical device should be sufficient. In large areas mechanical seeders properly calibrated should produce desired results more efficiently and effectively. When planting fine seed, it may be necessary to mix an inert carrier with the seed to obtain better distribution. Recommended inert carriers are sand or vermiculite. The recommended ratio for these carriers is 2:1 sand to seed.13. Once the seed has been planted, it must be covered to maximum depth of 1/8 to 1/4 of an inch. This can be accomplished by lightly raking the seed in with a hand rake for small areas, or by using a drag mat behind a tractor for larger areas. If a drill seeder is used, firm the soil after drilling with a cultipacker to insure proper seed/soil contact.14. Wildflower seeds need moisture for germination and growth. Supplemental watering may be necessary if there is not adequate rainfall. As the planting becomes established, watering may be reduced. While it is important for the wildflowers to receive water it is equally important to provide adequate drainage for certain species. Germination will vary from species to species and from seed to seed within the same species. Time periods for germination will also vary from as little as several days to as slow as several years.15. Once the wildflowers have finished blooming and set seed, the entire area should be mowed. Mowing the area will help to scatter the seed for the following years' growth. Wildflower areas should be mowed to a height of 4-6 inches and should be accomplished in October and November. Waiting longer than this to mow generally results in very wet conditions which could cause more harm than good when attempting to mow.16. If a strong weed or invasive grass population has established itself in the wildflower areas, it may be necessary to treat with a contact herbicide or translocated herbicide to kill the root system in order to give an advantage to the following years stand of wildflowers.La. Admin. Code tit. 70, § I-311
Promulgated by the Department of Transportation and Development, LR 17:204 (February 1991), LR 26:1661 (August 2000).AUTHORITY NOTE: Promulgated in accordance with R.S. 47:820.6.