Retaining Walls

Retaining Walls done the right way

After going to all the trouble of building a retaining wall, the last thing you need is for it to collapse because of mud and water damage at its base. Rock retaining walls are designed to hold the dirt behind them back, but they only work when the dirt drains and dries out. Before the wall's construction, examine the lay of the land to see the way in which the water siphons off it to incorporate the right drainage system into your rock wall.

Retaining Walls

Defined as an edifice or structure built to prevent soil erosion and keep dirt in place, retaining walls can be built at different heights. It all depends upon the depth of the excavation in front of the wall and the overall landscaping theme. The type of soil behind the wall plays a part in the choice of the building material for the wall and the drains you place in it. Well-built rock retaining walls stay in place by sheer force of the gravity or the weight of the rock. Taller retaining walls may need additional reinforcements to make them stronger.

Design for Water

Begin the design process by watching the land during a heavy thunderstorm. Identify where water collects to incorporate a runoff system for stormy weather. Walls that are 4 feet or taller require special drainage at the base of the wall in addition to any swales -- sloped drainage ditches -- that collect and direct surface runoff atop the dirt behind the wall. Walls built in clay soils or other dirt that does not drain well also need built-in drains at the base of the wall regardless of height.

Toe Drains

Keep water away from the site while excavating the area to build the retaining wall. Pay attention to any water seepage in the excavated area, as this indicates you need to add enough drains to keep the area dry. Add a gravel bed beneath the rock wall and directly behind it as high as it is tall, and at least a foot wide or more, against the wall before adding the soil. Toe drains -- typically, 4-inch pipes perforated to accept water seepage from the soil -- must be installed behind the wall at its base in the gravel parallel to the wall to collect water from the gravel and move it away from the wall. A toe drain must vent to daylight at its end, through the wall face or connect to an enclosed drain system.

Drain Pipes

For long retaining walls, you must vent parallel-to-the-wall toe drains at intervals of 30 to 50 feet. Add tee fittings perpendicular to the toe drain through the wall face to direct water to lower elevations, storm ditches or drains. Cover the opening of all daylight drains with rodent screens to ensure they stay clear. Mark their location to periodically check them to ensure they are not damaged and continue to drain.


Watering Basics


As a rule of thumb, a lawn needs about 1 inch of water per week - including any rainwater, so do not forget to account for that.  An easy way to determine how long to water your lawn is by doing the Tin Can Test.  Simply place an old tin can under the sprinkler and monitor how long it takes for it to collect 1/4 inch.  Using that time, multiply it by four (4) and that will be the time required to sufficiently water your lawn each week.  Using your best judgment, monitor your lawn and pull out the sprinklers (or pray for rain) when the lawn is looking a little dry.  There are consequences if a lawn is not watered during dry spells.  Lack of sufficient water can create stress on the lawn and can also weaken its natural defenses against weeds, insect pests and diseases.  The worst case scenario is that lack of water during extreme weather can have such an adverse affect that the grass could ultimately die.  

An inherent lawn-survival mechanism kicks in during the summer, where lawns can go dormant.  If your lawn goes dormant, water deeply once a month during the dry season (usually during the middle of summer) to put the lawn in the best position to withstand and survive the dry spell.  


A thorough watering is highly recommended after each BlueFox fertilization treatment.  Once applied, fertilizer typically sits on the top surface of the lawn where it has no effect.  A good watering will move the fertilizer down to the soil where it can do its magic and provide the root system with much-needed nutrients.  Ensure that the fertilizer is distributed evenly on the soil by completely watering all areas that is fertilized - you will avoid having patchy sections in your lawn because of uneven amounts of fertilizer be absorbed into the soil.


The best time to water is in the morning - there is less chance of being windy, which could adversely affect the ability to evenly distribute water and there will be more than sufficient time for the water to be absorbed and the grass to dry before the evening.  Grass that remains wet through the night increases the chance of lawn diseases.

To bag or to mulch - that is the Question.

Deciding whether to bag or mulch lawn clippings can be made in view of which advantages that suits you better. 


Grass clippings is not a factor in thatch buildup, nor does it increase the chances of disease. Clippings quickly and completely breakdown if your lawn is mowed at the right height, i.e., it is advantageous to keep more than 1/3 of the total grass height while mowing.  Grass clippings also contribute nitrogen and other nutrients that enrich soil, supplying additional useful organic materials. As much as 1-2 pounds of nitrogen can be added back into the soil from grass clippings from a 1000 sq. ft. lawn


Bagging is advantageous if you have a compost pile.  It is not necessary to add clippings to a compost pile each week so an alternating regimen of mulching and bagging may be suitable.  Grass clippings can add much needed green-matter to the compost pile.  To avoid a strong ammonia odor, grass clippings should be mixed thoroughly with brown matter.  Avoid adding to the compost any grass clippings that have had any weed control products applied - wait at least 3 mowings after these products have been applied before composting.