Managing waterflow and run-off in our gardens
Maryland’s weather seems to grow more volatile, with more frequent heavy storms of wind and rain. Periods of drought also prevailed here in early 2023. Thus, it is a wise precaution to prepare our lawns and gardens for both heavy rain and drought during 2024, as the two conditions can wreak havoc. Even the average annual rainfall in Maryland is about 50 inches.
The preparations you may want to make to protect your lawns and gardens from erosion will be part of what has come to be known as “hardscape” rather than landscape. Hardscaping refers to man-made elements of landscaping that use wood, brick, gravel, and other material to change the lay of the land, often to protect that land from wind and water erosion. Usually, it’s best to have a professional service do your hardscape…because it is hard, perhaps even backbreaking work.
But, if you’ve got some muscle-builders in the family willing to help, they can assist your lawn and garden hardscaping for potentially extreme weather ahead.
Let’s consider two approaches:
1. Repairing and redeveloping lawn and garden areas that are already prone to erosion.
2. Redesigning the land’s configuration to avoid future water runoff and drought conditions. Since it’s March and the rainy season is fast approaching, if it comes at all, let’s begin with repairs to areas you already know may be problematic.
Common Types of Erosion
You might make a visual survey, a walk-about to look for telltale signs of problems. Here are some common forms of erosion you might observe:
Splash: raindrops hit unprotected soil and splash up, taking the topsoil and leaving stains on walls and walkways. Sheet wash: flowing water from a natural or manmade source washes away topsoil. Tunnel erosion: falling water’s impact on unprotected soil drills into the ground, allowing more water to drill deeper, eventually causing an erosion tunnel and then a collapsed run.Deflation: rainwater erodes soil exposing rocks and tree roots. Accumulation: soil moved by wind and water creates dunes and berms and chokes up streams.
Steps to Identify Erosion
Look over your lawn and garden for noticeable slopes; more than a 33 percent slope is likely to cause erosion. You can go to YouTube or any handy gardeners web site to learn how to measure for yourself the slopes in your land, or you can call in a surveyor to give you that information. An experienced hardscape service should provide that information, too. Survey your lawn and gardens for ruts and crevices, areas that are beginning to collapse along hillsides and steep slopes. Stake these problem areas so you can see if there’s a pattern, a clear direction of erosion. Do the ruts begin near the downspouts and flow down a slope in the lawn? Are there animals digging or burrowing that form ruts that may be shallow but have potential for collapsing? Are the stakes marking spots where you’ve lost shrubs and/or trees in the last year or two? Draw a map of your lawn and gardens; try to make it to scale. In a bright color, mark the areas where the erosion has occurred. Identify and note the cause of each area of erosion if you can.
Devise a Work Plan for The Problem Areas
Here are some of the methods available to repair areas where the earth has been or is being eroded:
For general “wash away” of lawn or flower beds, an erosion control blanket is a useful option. In a woven “cloth” of straw, coconut, or jute, and seeds are imbedded. Spread this net or blanket over exposed soil. The imbedded seeds will soon germinate, take root, and the mat or cloth, which protected the seeds from birds foraging and heavy rain, will disintegrate. We’re all familiar with good, old-fashioned ground covers such as periwinkle, ivy, and pachysandra. They’ll eventually fill in and protect the soil. (Do not plant ajuga or mondo grass; they’re sneaky little guys and will soon pop up in all the wrong places, plus you’ll never get them out.) Baffles can sometimes solve the rut problem. Use gravel or river-rocks in the rut, being careful to partially bury them so they don’t just wash away. Wood ties can also serve as baffles, laid across the slope and buried sufficiently to prevent their being washed away too. Terracing is a bit more drastic, requiring a careful plan for flattening areas down the slope. This is usually reserved for severe slopes.
Proactive Redesigning
Once repairs have been completed and your lawn and gardens are restored, it may be wise to consider a few ways to prevent erosion and ensure conservancy of precious water during periods of drought.
Re-examine Sloping. You or your professional have identified any sloping terrain and the percentage of that slope. But what do you do with that information? Generally, if the slope is:
33% or less, application of mulch or planting of ground cover will suffice to protect the soil from erosion.
33–50%, drip irrigation, an erosion control blanket, deep-root vegetation can help.
Steeper than 50%, terracing, retaining walls, and riprap may be necessary.
Rain barrels at the base of all downspouts not only controls water flow but provide a means to conserve and use captured rainwater during times of drought or for general lawn and garden maintenance. Rain gardens offer an interesting visual component in your garden. Bowl shaped and shallow, they’re usually lined with pebbles and hardy ground cover. When heavy rains occur, properly located rain gardens serve as catchments for excess water which can then be slowly released into the earth. A word of caution: be sure the rain garden is not situated too near any building’s foundation, or a home’s septic system or well. Trees & shrubs: Don’t overlook the practical protection the roots of trees and shrubs offer, holding together hillsides and capturing topsoil. We all know the many advantages and delights that accompany the cultivation of magnolias, crape myrtle, maples, and oaks. Mulching lays down a protective layer over precious topsoil. Mulch holds moisture, releasing the moisture gradually to nourish plants and trees.
With a little help from Mother Nature, your work restoring and protecting your lawns and gardens from wind and water damage will be well worth the investments in time and resources when March winds and April showers come our way.
