Hydroseeding Vs. Hand Seeding on a Slope

Revegetion Challenges

• Grass is a fast and effective erosion control method, especially in the short term. Erosion and sedimentation threatens water quality and aquatic habitat. Conditions on disturbed sites on large-scale construction projects are daunting for revegetation. Exotic species usually outcompete native species after the native plant diversity has been destroyed. Compaction from heavy equipment and constant traffic harms the soil structure, lowers the water-holding capacity, alters the habitat for plants, and limits root penetration.

Hydroseeding

• Hydroseeding, or hydraulic mulch seeding, plants seed via a seed/mulch slurry. The slurry is sprayed from a tanker loaded on a truck or even helicopter. The slurry can contain a variety of additional amendments, such as fertilizer, tackifying agent, and green dye. Hydroseeding is a standard technique for reseeding large scale construction sites and slopes that have been stripped of vegetation. It's less labor-intensive and has access to steep slopes. Hydroseeding is most successful when applying seed and seeds plus mulch..

Hand Seeding, Broadcasting, Drilling and Plugs

• Broadcasting seeds, by hand or with a spreader, scatters seeds over an area with limited control. Seed germination varies according to where it lands. Hand seeding for large sites has been replaced by mechanized seed drills that place seeds exactly spaced and buried. Plugs are plants started in a growing medium such as peat moss or soil mixture in a disposable plug container. The growth cycle is nurtured so that it's well-rooted before planting. Forbs and shrubs can be started in plugs.

Hydroseeding or Hand Seeding

• Optimal revegetation for slope stabilization is a mix of grass, forbs (broad-leaved plants) and deep-rooted shrubs. Fast short-term growth and long-term establishment of vegetative cover is a goal of erosion control planting. Research by California Department of Transportation suggests establishing erosion control by hydroseeding grass cover for short term cover and months later install forbs and shrubs planted in plugs. This accomplishes rapid cover and plants that can resist competition from invasive species, improving biodiversity.