Mother Nature hasn’t been kind to the Denver Metro Area recently.  Heavy snows, and late record cold temperatures followed a winter (and summer and fall!) of drought.  It was great to see this display of garden resilience in one of my client’s gardens as I was doing the spring clean-up.  What made the difference here? 

Mulch.  My sustainability tip #1.  Mulch, in many forms can provide the following benefits:  it retains soil moisture, and reduces soil evaporation, reduces weed growth, and reduces soil temperature fluctuations.  The latter can cause heaving of shallowly rooted plants during a freeze/thaw cycle.  3-4″ of mulch is recommended as an organic, sustainable practice of weed control because the depth of mulch helps prevent weed seeds from setting as easily.  Less weed seeds means less likelihood of the need for later chemical control.  During a drought year, with watering restrictions, retaining soil moisture is the most important benefit of mulch.  

Perennial gardens, and other landscape areas look beautiful with a uniform layer of organic mulch.  Sourcing the mulch locally, or using a recycled product from an arborist or tree company is an additional way to promote sustainability.  As perennial gardens mature, and spreading plant material or groundcover plants fill in the bare areas, less mulch is needed.  Vegetable gardeners may choose to use straw, or grass clippings as organic mulches.  With the latter, it’s best to let the grass clippings dry before application to prevent matting.  Grass clippings from lawns treated with herbicides should not be used as mulch. 

When using organic mulch, it’s also a good idea to test for nitrogen deficiency in the soil occasionally.  As organic mulches decompose, surface soil nitrogen is used in the decomposition process.  If a soils test shows the need, nitrogen can be added to those areas where soil deficiencies occur.   

Check back for other sustainable garden maintenance ideas.