Step-By-Step Soil Preparation:
"Enhance a lawn's ultimate beauty and success by improving the soil before the installation takes place."
Why is good soil important
For optimum growth, turfgrass needs just four things (in the proper balance)...sunlight, air, water and nutrients. Reduce any one and the turfgrass will suffer or die. In the right proportions, turfgrass will flourish, providing beauty to the landscape, a clean and safe place to play, plus many other benefits.
Grass obtains three of the four essential factors (air, water and nutrients) from the soil, but many soils are less than ideal for growing grass. Some soils contain too much clay and may be compacted. While compacted soils may be great for roads they are bad for grass. If air and water are not available to the roots it will inhibit the growth of grass. Other soils may have too much sand. While sand may be beautiful on a beach, too much sand in the soil will prevent water and nutrients from staying in the root zone long enough for the palnt to use them. Another frequently observed problem with many soils is the pH. The pH scale measures how acidic or basic a substance is. If the degree of acidity or alkalinity in the soil is too high or too low it can effect the availability of nutrients to the plant and prevent optimum growth.
What is The Best Soil for Turfgrass
Loams, sandy loams and loamy sands, with a pH of 6.0 to 7.0 are the very best soils for producing a beautiful, high-use, low maintenance lawn. Unfortunatly, this ideal soil mixture is seldom found on any property after construction.
How Deep Should The Soil Be
The absolute minimum depth of quality top soil for a care-free lawn is 4 inches (10cm); however, for deeper root penetration and the benefits that they bring, the accepted standard is 6 inches (15cm).
Can Soils be Improved
Not only can most soils be improved, they usually need to be improved to get maximum results with only minimum effort.
The knowledge of what is necessary, the amount, and availability of materials, immediate costs and time are all factors that typically detour people from taking steps to improve soil.
Proper soil improvement and site preparation 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, use water and nutrients more efficiently and result in a denser and healthier lawn as new grass plant shoots emerge. A dense lawn crowds out weeds and offers greater resistance to insects and disease.
"The Beauty is in the blades, but the 'action' is in the roots."
Follow these simple steps 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 are any larger than 2 inches (4-5cm) in diameter.
- Rough grade the entire area to eliminate any drainage problems on the property. This would include sloping the grade away from the building foundations, eliminating or reducing severe slopes and filling low-lying areas. A tractor mounted blade and/or box are most often used for rough grading, but if the area is small, it can be done with hand tools. The rough grading, will probably uncover more debris that should be removed.
- Initial tilling to a depth of at least 2 inches (5cm), should be completed prior to adding any topsoil or soil amendments. This will control most annual weeds, alleviate subsoil compaction, permit a bonding of the topsoil to the subsoil and improve root penetration as well as air exchange and water movement.
- Add topsoil to acheive a total top soil depth of 4-6 inches (10-15cm), after firming. The topsoil should be a loamy sand, sandy loam, sandy clay loam or another soil suitable for the area.
- Test soil for Ph and nutrients to determine if any pH correcting materials or nutrients are required.
- Acidic soils: A pH of less than 6 can be improved with the addition of lime. The type (or source) and amount applied will be determined by the level of acidity and should be based on the recommendations of a professional
- Alkaline soils: A pH of 8 and higher can be improved with sulphur. As with acidic soil correcting materials, the type and amount of materials needed will be determined by the level of alkalinity and should be based on a professionals recommendation.
- Apply fertilizer to correct any deficiencies following the product's recommended rate. To avoid root injury to new turfgrass, the fertilizer should be raked into the top 3-4 inches (7-10cm).
- Finish grade the entire site, maintaining the rough grading contours and slopes, with a tractor-mounted box blade for large areas or a heavy-duty rake for smaller sites.
- Roll the area with a lawn roller one-third full of water to firm and settle the surface. Low spots should be filled to match the surrounding grade surface. If time permits, allow area to settle further with rainfall or by applying irrigation.
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- Sod is a living plant the requires moisture to survive. If your prepared soil appears to be dry, you can water the soil before installation. This provides a moist base for sod during installation. Moistening to a depth of 6 inches is recommended for most soil types.
- In hot weather, protect unlaid sod by placing pallets in shade, covering with moist burlap sacks, and/or sprinkling.
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The following reccomendations from The Lawn Institute (www.thelawninstitute.org) will help you maintain a thick, healthy lawn after natural turfgrass sod has been installed:
The type and quantity of fertilizer required for your lawn will depend on your grass variety. Cool and warm season grasses vary as do their nutrient requirements. Check with your Extension Service, local nursery or lawn and garden professional to determine what type of fertilizer is best for your lawn.
The turfgrass can be mowed when it is rooted. Be sure to remove no more than 1/3 of the grass blade. The actual height of the cut varies depending on whether the grass is a cool or warm season and the type of grass.
Keep your mower blades sharp. Dull blades tear the grass blade instead of cutting it cleanly. These small rips in the turfgrass tissue can cause the grass to lose more water, increase irrigation needs, create stress, and make the lawn more vulnerable to diseases.
Leave grass clippings. Contrary to popular belief, they do not cause thatch. (Thatch usually occurs only when turf is excessively fertilized and soil is compacted, cool and moist.) If you follow the 1/3 cutting rule grass clippings won't smother the grass plants. They will dry out and work their way down to the soil surface. These clippings return nutrients to the soil, resulting in less fertilizer use. They also cool the soil and help it retain water.
Thatch is a layer of dead and decomposing plant tissue that forms above the soil. A thin 1/2 inch layer is beneficial to the lawn. It protects plant crowns and reduces compaction. But if the layer gets too thick, water, air and fertilizer can't get through to the soil and grass roots. Runoff increases and dry spots appear. Or when it's wet, the thatch can remain saturated and suffocate roots. Thatch usually occurs on turf that has been heavily fertilized, and is most common on poorly drained, compacted and acidic soils. Some species of lawn grasses are more prone to those problems than others. Severe thatch problems left unattended may eventually require the use of a dethatching machine. To prevent or minimize thatch problems, core aeration is an option dpending on your situation.
Core aerators punch small holes in the lawn allowing air and moisture to penetrate through the holes. It is most effective in late summer when temperatures are starting to cool and the soil is only slightly moist.
After aeration, leave the soil cores on the surface to dry. Then rake them to distribute the soil down through the grass to mix with and dilute the thatch. The mixing action of core aeration is similar to that provided by earthworms. Core aeration can also help increase water infiltration on compacted soils. Contact a local landscape company for dethatching or core aeration service or check with your local equipment rental center.
- After installing sod, for best results roll the entire area to improve sod-to-soil contact as well as removing any air pockets that may have formed.
- Water areas near buildings more often where reflected heat dries the sod out more easily.
- During the first 3 weeks, avoid heavy or concentrated use of your new lawn. This gives the roots an opportunity to firmly knit with soil, and insures that the sod will remain smooth.
- You can mow your new sod lawn after 2 -3 weeks. The sod should be firmly rooted down and not able to be lifted from the ground.
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- Mow often, generally removing no more than 1/3 of the grass height per mowing. Keep your mower blades sharp and avoid making sharp or fast turns on riding mowers as this can pull up or rip edges and corners of newly installed sod that has not yet firmly rooted down.
- Fertilizer and chemicals can be applied to your new sod lawn as soon as 1 month after installation.
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