Reclamation can sometimes be difficult in droughty environments such as excavation sites. It’s for this reason that a considerable amount of research has been conducted in New Hampshire relative to different seed mixes and methods of planting that would yield the best chance for successful reclamation efforts. Mr. Ted Kelsey, now retired from the USDA Soils Conservation Service, was in the forefront of experimenting with a wide variety of seed mixes within test plots scattered around the State.
The primary resource that illustrates the knowledge gained by decades of reclamation research is Vegetating New Hampshire Sand & Gravel Pits.
Cool Season Grass Mixes
Generally, cool season grass mixes are used to reclaim depleted areas that have at least 4″-6″ of topsoil available for the seedbed. Mix 2 & 3 in the Vegetating New Hampshire Sand & Gravel Pits booklet are examples of this type of seed mix. Warm season grasses, on the other hand, can be planted on depleted area having little or no topsoil. The process of seeding is different, as illustrated in the second photo album.
Warm Season Grass Mixes
Warm season grass mixes offer superior soil stabilizing qualities under certain conditions. They plants develop a root structure which runs deeply into the ground. During early growth, these plants will develop their unique root systems in lieu of developing robust greens above grade. As the plants mature, the roots will be as long as the plant is high. If the plant stands 4′ tall, the roots will reach approximately 4′ below the surface. This trait alone serves to provide for superior soil stabilization abilities. This, together with their ability to tolerate droughty conditions, makes for a viable choice when considering seed mixes for reclaiming depleted excavation sites.
The plants will take longer to green-up in the Spring, but the yearly rate of growth can be impressive. Mix #1 in the Vegetating New Hampshire Sand & Gravel Pits booklet is one which should be considered when the following conditions are present: little or no topsoil exists for use as a seedbed and/or superior soil stabilization qualities are needed.