What is Hydroseeding?

To put it simply, hydroseeding is an efficient way to plant a lot of seed, and at the same time control erosion. This is done by mixing seed, water, mulch, fertilizer, and a binder in a specialized sprayer called a hydroseeder. There is a mechanical agitator inside the hydroseeder that blends everything up into a thick slurry. The slurry is then sprayed out directly onto the ground and forms a moist bed for germinating the seeds while protecting the bare dirt from getting washed out by rain.

The great thing about hydroseeding is this can be done quickly and economically even on large areas covering multiple acres.

Where to Hydroseed

Hydroseeding can be sprayed pretty much anywhere, but there are certain cases where it really shines.

• Hillsides or areas prone to erosion – Hillsides can be quickly stabilized with hydroseed while minimizing slope disturbance.
• Lawns – Hydroseeding is generally much less expensive than installing sod, and since any seed can be used it opens up more options for types of turf grass or lawn alternatives that may not be readily avialable as sod.
• Large spaces – Hydroseeding is much faster and cheaper than traditional landscaping so can be a good way to establish vegetation over big areas.
• Habitat Restoration – Areas with disturbed native habitats can be hydroseeded with seed mixes designed to reestablish specific plant communities.
• Natural settings – Using native seed mixes you can create anything from a flowering meadow to a sage covered hillside to help blend into the surrounding natural beauty.

How to Prepare for Hydroseeding

Hydroseed works best when sprayed on properly prepped bare soil. Adding amendments, tilling, and grading the soil helps seeds sprout and new plants thrive.

Start with removing any existing or unwanted vegetation. Afterwards, incorporate compost and fertilizer into the top layer of soil. It’s often worth the time to send a soil sample to a lab for testing to see exactly what kind of amendments would be most helpful.

Lastly, finely grade the soil throughout the area to be seeded, making sure to remove any rocks and break up any large clumps of dirt. The end result should be a smooth and even surface.

When to Hydroseed

Although you can hydroseed any time of year, the best time depends on the type of seed and if the area will be irrigated or not. Some seeds such as those for warm season grasses germinate best in the warmer seasons. Of course, in the San Luis Obispo area we don’t get much rain during the warm seasons so if you hydroseed when it’s dry you will want to have supplemental irrigation to make sure the seeds can sprout and grow.

Other seeds such as annuals, cool season grasses, and some native shrubs germinate best during the cooler wet seasons. This also works well when you are not planning to water the hydroseeded space.

If the hydroseed will be sprayed on a hillside or for erosion control, it is best done in the fall prior to substantial rainfall so that soil is not washed away. Hydroseed in this case, often works in conjunction with other erosion control measures and BMP’s (Best Management Practices).

Lastly, if a heavy downpour is expected right after hydroseeding is scheduled you may want to hold off. Light rain is fine, but heavy rain comes with the risk of washing out the freshly applied hydroseed mixture. Some hydromulches (the term used for the mulch added to the slurry) resist washout better than others though, so proper selection is important especially on steep slopes and during wet weather.

What to Put in the Hydroseed Mix

At it’s simplest, a hydroseed mix includes water, seeds, and hydromulch. From there, other ingredients can be added depending on soil conditions, type of seed, type of hydromulch, and soil fertility. Often a binding agent or tackifier such as guar or psyllium is used. This tackifier is the glue that holds all the ingredients together. Fertilizer is another common ingredient. A soil test prior to hydroseeding can determine the type and amount of fertilizer to use.

The most fun part of the mixture is the seed. Pretty much any type of seed can be included. Specialty bulk seed suppliers carry inventories of native and non native seeds which can be custom mixed or you can choose a pre-selected mixture. Popular choices for the Central Coast include a Coastal Flowering Meadow mix, Chapparal Mix, Coastal Sage Scrub mix, Native Fescue mix, and a Pollinator mix. These all work very well for our area. For more info on locally available seeds, you can browse the inventory at Pacific Coast Seed.

What to do After Hydroseeding

Finally, after the hydroseed has been sprayed its time to ensure the new plants can thrive. One thing to note is that different types of seeds take varying amounts of time to germinate. Some take a few days while others may take weeks. So don’t worry if it takes a bit for everything to start sprouting.

The most important thing is to make sure the seeds don’t dry out before they can sprout. Frequent light watering (or rain) will help with this. Even after the new plants come up keep the ground moist to help the young roots get established. Quality hydromulch helps a lot when it comes to keeping the seeds damp. It holds moisture and can decrease the amount of rain or irrigation needed for germination. In most cases, a native seed mix sprayed in the fall as the rainy season starts won’t need much (if any) supplemental watering to grow, but this is dependent on the weather and seed type so talk to your hydroseed installer about water requirements for your specific circumstances.

If done properly, hydroseeding is a wonderful and functional way to create a naturally beautful space. Contact us to learn more and get a fast quote for your hydroseeding project.