Soil preperation
How to Prepare for Hydroseeding
Properly prepared soil will directly reflect the health and appearance of the lawn for years to come. At the very least, we need a loosely raked surface, free of existing vegetation, on which to apply the hydroseed mix.
A high percentage of the plant and turf problems can be traced to and/or caused by poor soil environment. Construction sites become severely compacted which results in loss of space between soil particles and this impedes the movement of air, water and the ability of the roots to penetrate through the soil. The addition of a few inches of topsoil, spread over the top of compacted soils does little to improve the situation. The end result is a shallow rooted lawn that is highly susceptible to drought during the summer and flooded roots during the winter.
The best approach to correcting this situation is to amend the existing soil by tilling a decomposed organic matter into the existing soil (i.e. fertile compost, peat moss, etc.). If this approach is not possible due to rock or other reasons then the second option would be to import topsoil and spread to a depth of at least 6 inches.
Remember, "Anything you want to grow is ONLY as good as what it is grown in."
Proper site preparation and soil improvement, before any planting takes place, will make it easier for the grass roots to penetrate deeply and evenly. Deep roots will make the lawn more drought resistant, a more efficient water and nutrient user and more dense as new grass plant shoots emerge. A dense lawn crowds out weeds and resists insects and disease.
Follow the steps below for a beautiful, healthy and trouble-free lawn:
Clear the site of all building materials (wood, cement, bricks, etc.), as well as any buried stumps, rocks, stones or other debris that is larger than 2-3 inches (4-5 cm) in diameter.
Rough grade the entire area and eliminate any drainage problems. This would include sloping the grade away from building foundations, eliminating or reducing severe slopes and filling low-lying areas.
Use a tractor-mounted box blade for rough grading large areas. Use hand tools for small areas. Rough grading may uncover more debris to be removed.
Initial tilling, to a depth of at least 2 inches (5 cm), should be completed prior to adding any topsoil or soil amendments. This will alleviate subsoil compaction; permit a bonding of the topsoil to the subsoil; and improve root penetration and water movement.
Add topsoil to achieve a total topsoil depth of 4-6 inches (10-15 cm), after firming. The soil type should be loamy compost mix. Dark nutrient rich topsoil provides a fertile soil environment for the top 8 inches of soil.
If timing allows, conduct a soil test. The test results will give you a report on the nutrient levels, CEC (cation exchange capacity), and pH along with recommendations on correcting any deficiencies. Following the recommendations may include correcting acid or alkalinity levels, adding soil amendments and/or adjusting fertility. If amendments and fertilizer are added, work them into the top 3-4 inches (7 to 10 cm) of the soil. If this cannot be done before planting it can always be done later in smaller doses using a spreader.
Finish grade the entire site, maintaining the rough grading contours and slopes, using a power rake on large areas or a aluminum grading rake on smaller sites.
If you added more than 3” of new topsoil roll the area with a lawn roller one third full of water to firm and settle the surface and reveal any low spots that should be filled to match the surrounding grade surface. If the area has been rolled scratch the surface once again to add texture so the hydro seed can bind with the soil particles. You should be able to stick your index finger in the soil up to your second knuckle with ease.
This site is now ready for Hydro Seed.
Follow the post-installation procedures and develop a long-term maintenance program to insure your new lawn will be a beautiful, useful investment for years to come.