Why Dye Mulch? by Charlie Plonski
Spring 2000 Volume 14, No. 1

Over the last few years I have noticed a great deal of bark and wood chip mulches being used that are dyed some tone of orange. Their use raises some issues for me both horticulturally and aesthetically.

Every winter gardeners plan their gardens with great care. Plant varieties researched, color schemes planned, designs refined. Spring finds us visiting nurseries selecting the best Vermont Grown plants to grace the garden with their living, breathing presence. Time and money spent to enhance your landscape. The plants and their layout is what garden visitors should be admiring, not a mulch whose color I've yet to see in nature.

Woodchips present a different problem in the garden. Culturally, the use of hardwood chips - dyed or plain - should be avoided. Because the chips are not finely ground they will needlessly rob vital nutrients from the soil to aid in decomposition. This will have a detrimental effect on the plants you mulch (especially annuals & perennials) causing them to look ill or under nourished. Partially decomposed, finer ground softwood mulches donÕt present as much of a problem.

Now bark mulch, if used properly, serves a very functional purpose in the landscape. Partially decomposed, double-ground bark mulch conserves water in the soil while helping maintain consistent soil temperature. It suppresses weed growth and eventually adds organic matter to the upper soil profile. All the while giving established beds a fresh tidy look in spring.

Over time, bark mulch decomposes and can be safely incorporated into the soil. However, the process of decomposition, even with finely ground softwood mulches, can deplete the supply of nitrogen available to your plants. We have found this especially true with annuals and perennials. If you use mulch on annual and perennial beds, top dress the garden with Farm-Crafted Compost or Pro-Gro fertilizer before mulching lightly.

For new beds, first dig and remove the sod from the bed. This sod can be incorporated into your compost pile. After you have planted your shrubs or trees spread a 3-4 inch layer of mulch. A word of caution NEVER PILE MULCH AGAINST A PLANT'S STEM OR TRUNK!! Your 3 inch layer will eventually settle to 1/2 of its original depth. Each spring, re-mulch with 1 1/2 inches to freshen the look, being careful not to accumulate too thick of a layer.

One key to suppressing the weeds is to dig a deep edge between the bed and the grass. Try to make a 4" vertical slice into the soil, which you can then fill with mulch. This slice, or edge, will suppress grasses and weeds from migrating from the lawn and surroundings into the bed.

When re-mulching shade trees it is a good idea to remove last year's mulch before applying fertilizer and new mulch. If you allow mulch to accumulate year after year, the tree's fine roots will begin to grow up into the mulch causing the tree to become more susceptible to stress during dry periods. Mulch rings should be 6-8' in diameter and 2-3" deep, making sure to leave the area near the trunk bare.

Understated and functional, non-dyed bark mulch has a place in the landscape without being visible in the dark. This year Horsfords has a steady supply of bulk pine or hemlock available. Hemlock is more reddish-brown in tone and seems to hold its color better through the season while pine is earthy brown in color. Both are available for pick-up or delivery.