Extension > Garden > SULIS > Maintenance > Sustainable Lawn care Information Series > Establishing a New Lawn to Achieve Sustainability > Seeding Rates and Planting Methods - Hydroseeding and Hydromulching
Seeding Rates and Planting Methods - Hydroseeding and Hydromulching
Hydroseeding and hydromulching are a couple of seeding variations available from professional installers. While the terms are used somewhat interchangeably, they are distinctly different processes. With refinements in both application technology and equipment, either method can work very well when it comes to establishing a new area from seed.
Hydroseeding involves spraying a liquid mixture of grass seed, mulch and fertilizer over a prepared soil surface. The mulch consists of a wet pulpy material to which the desired grass seed and (usually) some starter fertilizer have been added. This can be very effective method of seeding difficult to reach areas, sloped areas or other situations where it is problematic to get in with traditional seeding equipment.
Hydromulching, on the other hand, involves spraying a similar pulp-like mulch material over an area that has already been seeded and (usually) fertilized. This process can also be used in similar applications to hydroseeding. However, where doing the actual seeding is problematic due to slopes, or difficult to reach areas, hydroseeding will usually be more practical.
A homeowner version of hydroseeding is available in the form of bagged mulch material that already comes with seed mixed in and occasionally a fertilizer added. In this instance the material is spread over the surface in its dry form and then moistened to form the "mulch mat" over the surface.
If proper seeding is done first, these same materials or mulch materials without the seed or fertilizer added, can be spread over the soil surface in their dry form and then watered-in to create the same effect as a hydromulch. In either situation, remember to maintain the area in a slightly damp condition until the seedlings have begun to emerge and establish themselves.
Post installation care is similar to that required for any other newly seeded area. While there is the added protection of the pulpy matrix covering the seed, it is still necessary to make sure that it does not excessively dry out - a fatal situation for newly germinated grass seeds. In addition, as the seedlings begin to emerge through the mulch they may need some additional nitrogen fertilizer to make sure that uniform, vigorous growth is sustained. This helps them get established more quickly and provide some early competitiveness against potential weed invasion.
The pictures below shows a situation where there was insufficient fertilizer, particularly nitrogen, used to sustain early healthy, vigorous growth in a hydroseeded site. Hence, notice the large numbers of weeds that have been able to germinate and begin to get established. This situation will require some overseeding and weed control measures to bring back a more competitive stand of turfgrass.
Insufficient fertilizer reduces early, healthy, vigorous turfgrass growth and allows for invasion of many different weed species.