From Volume 2, Number 12, December 1997

We strive to prevent the loss of soil in the landscape, as well as to create beauty. With our plantings, we hope to encourage a strong net of roots to bind loose soil and a dense canopy of foliage to break the impact of falling water.

The single fastest way to cover bare ground with living plant material is to hydroseed it. Hydraulic seeding is a specialized niche in the green industry. A hydraulic seeding technician needs the skills of a chef to mix a slurry of perfect consistency and the hand of an airbrush artist to spray out a fine and even application.

Micke Santoro, owner of Southern California Hydroseed and Hydromulch, Inc., recognizes this. Experience has shown him that techniques that work well with an experienced applicator can be disastrous in the hands of a novice. Santoro teaches other industry professionals from all over the world, because he believes for each individual project well done the green industry as a whole benefits.

The slurry is the foundation of every hydroseeding job, and the seed is the least of it. A typical mix, sufficient to cover a half acre, contains 1,000 pounds of wood fiber, 150 pounds of fertilizer, 75 pounds of binder and 3,000 gallons of water. The seed itself is a relatively minor weight, and the very last item to be placed in the tank.

Mixing seed, water and fertilizer together makes sense; the mystery items in the slurry to those of us who do not hydroseed are the fiber and binder. The wood fiber helps to disperse the seed evenly throughout the slurry during agitation and acts as a mulch after application. The binder is literally a glue. The stuff sets up pretty fast too, so any slurry unintentionally applied needs a light spray down with water right away to remove it.

Hydroseeding is an installation specialty that fulfills a variety of landscape needs: erosion control plantings, seasonal color, environmental mitigation and turf -- from residential lawns to golf courses. Proper care of a newly hydroseeded are can be summed up in two words: water it. But like very other aspect of hydraulic seeding, there's more to it than that. Hydroseeding lifts the glass of the greenhouse and spreads the seed flat over acres. The surface must be kept evenly must at all times until the seed germinates and the new plants have grown on for a minimum of two weeks -- not soggy, moist, and never, never dry. A new application will cut you no slack for Santa Anas or dead backup batteries in the clocks. Seeds that have begun the process of germination and then dry out, die.

A common complaint against hydraulic seed mixes is that they come on in a flash, but burn out and fade away just as quickly. A look beneath the fiber mulch, at the soil, provides an answer. Consider the cut and fill nightmares hydraulic seeders are asked to cloak. Hydroseeding is a technology for putting down seed, not a magic carpet. Soil deficiencies reveal themselves in the health of plants here, as they do in landscapes installed by every other method. The most vibrant, long-lived hydroseed applications are sprayed on good soil.

Most hydroseeding companies are specialty operations that work as subcontractors to landscape contractors. Very few traditional landscape companies dabble in hydraulic seeding along with the rest of their work. Even many of the largest companies hire subs rather than run their own rigs. Why? Maybe it's the long apprenticeship necessary to develop good technicians. Maybe the constantly shifting focus of the hydroseeding market demands a specialist to stay on top of it.

New products for soil improvement are creating additional opportunities in hydraulic seeding. Blowing on a straw mulch is nothing new, but the applications of humus and gypsum are on the rise. One job site that called for a single application of slurry before, might now require two or more phases: humus and/or gypsum, the slurry, straw mulch and/or fiber matting.

Getting the soil covered before the rain comes to wash it away is a perennial problem in the Southwest -- a region with neither soil nor rain to spare, and a cataclysmic growth rate. Hydraulically seeded plant material, well applied and maintained after application, can become a solid carpet of erosion control within a month. If you look on the hydraulic seeding niche from the outside in, hang onto the business card of the best practitioner you know, because some day coming, you'll need it.
Leah Rottke is a contributing editor to Southwest Trees & Turf.