The Magic of Mulches

by Carole McCray

Mulch can work wonders for a garden.  Organic mulch is a biodegradable plant material like wood chips and is good for a flowerbed.  Inorganic material such as plastic sheeting is better in a vegetable garden.  Your Growise Center will advise you on the best mulch for your garden.

ORGANIC MULCHES

Bark—place a thickness of 2 to 4 inches around trees, shrubs, perennials or pathways.   Replace annually.  Small chips are attractive; large pieces retard weeds better.  Aged bark prevents nitrogen depletion in soil.

¨     Cocoa hulls—place a thickness of 2 to 4 inches around trees, shrubs, perennials or herbs.   Pleasing color.  May contain pesticide residue; can mold.

¨     Compost—Apply 2 to 4 inches around vegetables, flowers or fruit.  Good source of organic matter.

¨     Mushroom compost—good source of organic matter.  Apply thickness of 2 to 4 inches around vegetables, flowers or fruit after soil warms.  Can be turned under at end of season.

¨     Rotted manure—Same as mushroom compost.

¨     Wood chips—Apply a thickness of 3 to 4 inches around trees, shrubs, herbs or perennials.  Compost before applying or add nitrogen to fresh chips. 

  BENEFITS OF ORGANIC MULCH

Keeps plants healthy.  Improves soil structure and nutrient content as mulch             slowly degrades.  Retards weed growth. Slows water evaporation. Soil does not dry out quickly; less watering required. Helps soil stay cool; reduces stress on plant roots in summer heat. Acts as a ground insulator in winter.  Protects plants from heaving out of the soil in climates where ground freezes and thaws rapidly. Can prevent soil from washing away in hard rain.

 INORGANIC MULCHES

     Landscape Fabric—weed barrier around trees and shrubs.  Lay out before        
     planting;      then cut holes for plant material.  Cover with a 2-inch layer of mulch.  If  
     exposed to      sunlight, breaks down after several years. Tough weeds may come 
     through.

      Plastic sheeting—place around trees, shrubs, vegetables and flowers.  Apply before planting; then cut holes.  Apply a thin layer of organic mulch to disguise sheeting.  Exposure to light causes sheeting to break down in two to three seasons.  Sheeting raises temperature; lay soaker hose underneath to water.

     Gravel or small stone—natural looking in the proper setting.  Stone is well-suited in a dry climate; dark --natural looking in the proper setting.  In cold regions, spread landscape fabric beneath gravel or stones.  It keeps mulch from working its way into the freezing and thawing soil and prevents formation of large air pockets, causing roots to dry out.

WHEN TO MULCH

      Mid spring; wait till perennials show new growth. Apply a winter mulch to protect perennials once the soil freezes.  Lay a 6-to12-inch layer of straw over summer mulch. Rake off winter mulch in early spring.

PREVENT MULCH PROBLEMS

     Keep mulch 6 inches away from plant to discourage slugs, cutworms and earwigs that may hide under mulch.  Never mound up mulch around tree stems. Avoid light-colored mulches in cooler climates; they prevent soil from warming in spring.  Use light-colored material in the South where soil can heat too fast in summer. Mulches like straw and sawdust can cause nutrient imbalance; replace nitrogen with bloodmeal or other nitrogen source. Your Growise specialists will help you work magic in your gardens with a variety of mulches.