Choosing the Right Ground Cover

In this week’s Blog, I would like to discuss how to choose the right ground cover for your situation.  Gone are the days when we have exposed soil.  Today there are many options and opportunities to do very creative things with ground covers.

First off what is considered a ground cover?  Essentially a ground cover can be defined as anything that covers the sub-strait or soil.  So what kind of options are there?  Literally there are thousands of different types of ground covers, but I would like to focus on a couple.  Wood mulch (Large-medium, small and interlocking) and decorative rock.

Looking at wood mulch there are many varieties of sizes and types so it can be difficult to choose the right one.  Begining off with a coniferous wood mulch with a higher pH, is a good start.  The higher pH will help suppress weeds from coming through.  a minimum of 3-4 inches will further insulate the soil to help with environmental extremes, such as weather that is too hot/cold or dry.  It is important when using small or interlocking wood mulch NOT to use a filter fabric below.  There are two key reasons for this: first wood mulch will naturally bio-degrade adding nutrients into your garden, so it is important not to block this process. Second, because the mulch will bio-degrade it will create a growth medium above the filter fabric thus rendering it completely ineffective.  When using large or medium chip wood mulch there is so much space between each piece that weeds will easily germinate and so I would recommend using a 5 ounce filter fabric in this case.  Keep in mind that you will need to replace large and medium wood chip every so often to keep the fresh appearance and minimize weed infiltration.  Conversely with small and interlocking wood mulch you need only turn the mulch once a year to keep it looking new.

Strengths:  Keeps soil cool, adds nutrients, maintains moisture in soil, most products are organic, one of the most cost effective materials.

Decorative rock can be beautiful, however all too often people over use this, or use only one type and lose any natural look a decorative rock may offer.  Like large chip wood mulch, decorative rock must have filter fabric for effective weed suppression. I would suggest pinning the edge of the filter fabric with a pressure treated 2×4 to seal any adjacent concrete surfaces from weeds.  Unfortunately decorative rock can damage the trunks of trees and shrubs, and can seriously damage perennials.  Rock does not add any nutrients and adds very little thermal barrier.  The depth of rock should be a minimum of 3″ or double the diameter of rock; for example, if you choose a 4″ diameter river rock you should have a minimum depth of 8″ or if you choose a 10mm rundle crush you should use 3″.  Be sure to excavate your beds down where adjacent to other materials to accommodate your depth of rock.  Keep in mind rock can be quite expensive.

Be creative with your ground covers, do not use only one type or size.  Add a little variation for a more natural look, and remember that only one ground cover used in excess will be boring and ultimately not look very good.

Keep bringing your outdoor living dreams to life!

William Packolyk

Associate AALA, Blarch