May the Mulch Be With You

May the Mulch Be With You

Mulch is a natural way to enhance organic matter and retain moisture in urban soils. May is one of the best times to apply mulch to your landscape for maximum benefits.

I confess. I love mulch.

Mulch is a natural way to enhance organic matter and retain moisture in urban soils. Mulch is available in both organic and inorganic forms, and it comes in different shapes and sizes.

Most people think of mulches as raw or partially decomposed pieces of wood or bark. While this is true, mulches also may consist of black plastic, straw, pine needles, pecan shells and decomposed granite.

All mulches reduce soil moisture loss, but I prefer the organic varieties because of the carbon they add to the soil. Carbon is the energy food for all micro and macro organisms living in the soil and essential for the health of the environment.

Inorganic mulches like decomposed and rolled granite are added to the landscape with the assumption they facilitate drainage for xeric plants or reduce maintenance. But that’s not really true. They seldom provide any nutritional benefit and actually increase urban heat, flooding and maintenance so we very rarely recommend inorganic mulches.

Organic Mulches

  • Hardwood chips or shreds
  • Bark chips or shreds
  • Pecan shells
  • Straw
  • Pine needles

Inorganic Mulches

  • Rock of various sizes
  • Decomposed granite
  • Black plastic
  • Rubber chips

What else can mulch do for you? Mulch reduces soil temperature to facilitate root growth, inhibits weed germination and growth, provides soil structure that allows air and water to penetrate, and encourages beneficial soil organisms like bacteria, fungi and earthworms.

We strongly advise applications of mulch in May and September to achieve maximum benefits, so now is a great time for that mulch application. Your locally owned nursery has just the product for your landscape.

May you mulch to your heart’s content.

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Mark Peterson

About our expert

Mark Peterson

Mark A. Peterson is a conservation project coordinator for San Antonio Water System. With over 30 years of experience as an urban forester and arborist, Mark is probably the only person you know who actually prunes trees for fun. When not expounding on the benefits of trees and limited lawns, you’re likely to find him hiking San Antonio’s wilderness parks or expounding on the virtues of geography and history to his friends.