Archive for October, 2009

 The damage to concrete most people fear is actually caused by the freezing and thawing of water that soaks into the upper surface of the concrete. The use of deicing salts increases the amount of freeze-thaw cycles that a concrete sidewalk or driveway experiences. The volume of water increases by 9 percent when it freezes. This expansion creates internal pressures that can blast apart weak concrete.

Concrete that contains small air bubbles (air entrained), a minimum of 564 pounds of cement (6 bag mix) per cubic yard and a minimum amount of water when mixed (4 inch slump) can resist repeated episodes of ice expansion within the concrete. In addition, the concrete must be moist cured at or above 50 F for a minimum of seven days, produce a 28 day strength of 4,000 pounds per square inch and have a minimum drying time of 30 days before it is subjected to the first freeze-thaw cycle. These practices are commonly followed by experienced, professional concrete masons.

Deicing salts rarely cause problems on wood surfaces and asphalt. What little damage they may cause is far outweighed by the benefits of preventing personal injury as a result of a fall on some ice.
There are four primary deicing salts. All have different characteristics. The most common deicing salt is regular rock salt or sodium chloride. It is widely available and can melt snow and ice until the temperature drops to between 16 and 20 F. Below these temperatures the rock salt stops melting snow and ice. Rock salt also releases the highest amount of chloride ions when it dissolves. Chloride can pollute streams, rivers and lakes. The chloride also causes metal to corrode.

Calcium chloride is another deicing salt. Many people have seen these small rounded white pellets. It can continue to melt snow and ice as temperatures fall well below 0 F. It can cause skin irritation if your hands are moist when using it. Concentrations of calcium chloride can chemically attack concrete.
Potassium chloride is a deicing salt that available in some markets. It is not a skin irritant and does not harm vegetation. It only melts ice when the air temperture is above 15 F, but when combined with other chemicals it can melt ice at lower temperatures.

The newest deicing salt is magnesium chloride. It continues to melt snow and ice until the temperature reaches -13 F. In the photo, the air temperature was 0 F. The magnesium chloride melted through a 1/2 inch thick layer of ice in just 10 minutes. This salt releases about 40 percent less chlorides into the environment than either rock salt or calcium chloride. It is also less damaging to concrete surfaces of questionable or unknown quality. Magnesium chloride is less toxic to plants, trees and shrubs. It also does not leave a powder residue when tracked into your home.

Avoid the use of fertilizers as deicing and traction agents. Those that contain ammonium nitrate and ammonium sulfate can rapidly disintegrate concrete. Don’t take a chance if you don’t know what is in the fertilizer. If you don’t have salts available use sand to stop you from slipping and sliding.

Common Questions:

Is it necessary to wave a magic wand and remove every single leaf when doing a fall clean up? Is it acceptable to grind leaves and return them to the soil? Is it okay to place leaves in the surrounding wooded common area as long as they are spread evenly and not left in piles.  Are we being green??

Follow this link for modern leaf removal methods and the research that supports it.

MODERN LEAF REMOVAL

Traditional Methods

The traditional concept of creating huge piles of whole leaves and transporting them to a landfill is costly and not environmentally friendly. Large armies of workers using lots of noisy, smelly leaf blowers together with rakes and tarps have been the usual manner of removal.  Blowing and tarping of whole leaves and dragging them into huge piles take a good deal of time and thus heavy expense for the client. Transporting large quantities of leaves to a landfill is costly and deprives the soil and woodland areas of needed nutrients.

 Modern Methods

The modern choice is to mulch and reduce leaf size using specialized equipment. This method saves time on the site, reduces landfill transportation and dump fees, as well as provides direct environmental benefit to the turf and surrounding wooded areas.

Grinding leaves on the site with precision mowers reduces the need for blowing and also the amount of leaves to be piled. The pulverized leaves are returned to the thatch layer and provide benefit to the turf with both nutrients and soil composition. Leaf reduction in rear areas allows for the pulverized leaves to be returned to the surrounding wooded areas in a fashion that is eco friendly and not an eyesore to the client. This saves valuable tarp dragging time.

With less leaves to pile there is much less quantity to transport to the landfill area, which saves dump fees. As an added benefit, the leaves that are carried away are ground in such a way as to accelerate the decomposition process. This creates rich top soil that can later be transported back to properties that would benefit from it.

Research to Support our Methods:

The modern way of leaf removal

Virginia Cooperative extension endorses this approach!.  Virginia Tech,Turfgrass Specialist Michael Goatley Jr. believes:

“Leaf mulching directly into the turf. There are several university research reports detailing how leaf mulching affects turf performance. In almost every instance, the results show that chopping up deciduous leaves as part of a regular mowing schedule is an effective means of managing them without harming the turf. that in almost every instance, the results show that chopping up deciduous leaves as part of a regular mowing schedule is an effective means of managing these leaves without harming the turf.

Purdue University turfgrass researchers Zac Reicher and Glenn Hardebeck took the time to perform a study on the question and they found:

            Leaves have no effect on turf visual quality or color

            Leaves have no effect on turf growth  by clipping weights

            Leaves have no effect on mat or thatch depth

            Leaves have no effect on soil pH or nutrient availability

            Leaves have no effect on incidence of red thread

            Leaves have no effect on incidence of  pink patch.

            Leaves have no effect on incidence of  dollar spot

            Leaves have no effect on weed infestation

The Sierra Club, a non-profit, member supported, public interest organization that promotes conservation of the natural environment by influencing public policy decisions (legislative, administrative, legal and electoral) believes in leaving the leaves.

They state that leaf mulching:

Makes nutrients more readily available in the soil and speeds up the Enrichment process.

Retains water in the soil during the summer, for drought protection.

Insulates the ground from penetrating cold during the winter allowing the underground.

Work of earthworms and soil microorganisms to create Humus

Helps reduce weeds

“Brown patches are all over your property” exclaims a frustrated property manager.    If you have these troublesome brown patches on your property that have gotten increasingly worse with time, you may well have a Japanese beetle grub infestation in your lawn.  While chemical options are available, there is a safe, effective remedy in using Milky Spore. 

We’re all familiar with the damage the adult Japanese beetle does as it feasts on fruit, flower, shrubs, garden plants and the foliage of some field crops. At the immature beetle stage, the grub enjoys feeding on the roots of grass and other vegetation to include stems of plants.  Applications with Milky Spore attack the beetle at the grub level BEFORE damage is done.  Milky Spore acts as an on-guard protective blanket on your lawn and works for at least 10 years. 

Milky Spore is safe as opposed to the many dangerous chemical applications.  Milky Spore is not harmful to beneficial insects, birds, bees, pets or man. The product is approved and registered with EPA, Milky Spore will not affect wells, ponds or streams. The ideal way to combat area infestation is through organized community efforts. Large areas treated with Milky Spore can result in long term control.

Blade Runners issues a Milky Spore certificate for properties and communities that use this product on their turf area that can be used for future home sales or in community newsletters.

Milky Spore has gone through many transformations.  The product that Blade Runners uses is the original formula devised by the USDA, produced by St Gabriel laboratories, that has been proven effective for over 70 years to limit Japanese Beetle grub infestations.  Milky Spore is effective, innovative and on the cutting edge of environmental friendly products.

Common Questions: What changes are taking place in the mulch industry? What is mulch made of anyway? Why is the mulch looking worse each year?

 Great questions and it’s true that the quality of mulch you see on your property has changed considerably in the last decade. A combination of market force, competitive pricing, supply and demand, and alternative fuel requirements is putting the squeeze on your mulch quality. Click here to find out more and what you should be thinking about and how you should change your contract specifications.

What is Mulch?  Mulch is a protective covering, usually of organic matter, placed around plants to prevent the evaporation of moisture, the freezing of roots and the growth of weeds. We mulch to keep watering requirements low, protect the roots of plants in the winter, keep weeds down, enrich the soil and for aesthetic reasons.

While in the old days mulch was primarily made of shredded bark, shredded wood mulch is generally used in the Washington Metro area.  This is from shredded trees in area land clearings or bark from sawmills. 

Why is the mulch looking worse each year?  There has been a spike in demand for mulch products from this busy building cycle. Large price-based mulch contractors have entered the market using lower grade materials making it difficult for others to remain competitive. Using lower quality mulch has been a savings point for contractors one that they feel clients will not perceive.

• Factors that contribute to mulch quality:
  • Percentage of Bark- This represents the largest change. In years past, bark was made up of 100% shredded bark. Now mulch contractors must pay more for lower quality mulch. Once a principal supplier, saw mills are now selling their mulch to other companies who are trying to meet alternative fuel government requirements. Even the top quality mulch has only 70% bark and the majority of mulch being spread today has only 30-40%.
  • Age of shredded bark after processing – After the mulch is made aging is an important factor in quality. The natural decomposition will give mulch better and longer lasting color.  It will also bond together and avoid washout issues in the bed.
  • Degree of shredding- Some manufactures require double shredding and some do not. It is more a matter of the type of machine that is used. Smaller pieces will decompose faster and tend to look better on the landscape.
  • Presence of stump and undesirable items- Certain types of tree/stump debris will off balance the  percentage of bark. Stump debris has been known to cause a grey color as the mulch ages.  

What should you do?

Require your contract to adhere to these three minimum standards:

1)      Mulch to be 70% bark

2)      Mulch not to have pieces of wood longer than 3” and wider than ¼”

3)      Mulch not to have stump debris

What’s new on the market?  Colored mulch is gaining popularity in the landscape industry for its durability and aesthetic quality!  As an alternative, mulch with no bark and that is finely shred and has color added is being manufactured. It generally costs more but holds it’s color longer and can save on future mulch applications.  This could be real savings for properties that have more than one mulch application per season.