Cone Of Death
In The Garden – By Stephen and Kristin Pategas
We have evaluated communities for America in Bloom in 19 different states nationwide and have seen eruptions of conical mulch mounds surrounding trees in most of them. They have even appeared in Winter Park on newly-planted trees. One term commonly used for this abusive practice is – volcano mulching. It is unknown where it first appeared or why it occurred. Perhaps landscape contractors were looking for a way to increase profits by using more mulch at each tree ring or didn’t know what to do with excess mulch. We suspect it has spread due to the “monkey see, monkey do” syndrome. Many practices such as this one spread through copycat actions while research shows the practices are wasteful or even harmful.
In this case, many Cooperative Extension Services and other knowledgeable organizations rail against cones of mulch. The use of an excess amount of mulch in these non-sensical formations is a waste of mulch and a threat to the health of the tree for numerous reasons.
A thick layer of mulch prevents water whether from rainfall or irrigation, from penetrating to the roots. Especially for a newly planted tree, lack of adequate water is certain death.
- Mulch piled against a tree trunk keeps it moist and the over-saturated cells make it susceptible to diseases. A weakened tree is then more vulnerable to pests.
- Roots grow upwards into the mulch seeking oxygen and moisture. They may become girdling roots which expand in diameter and hug the trunk. They cut off some of the tree’s vascular system and compromise its growth.
Check each tree to make sure the root flare is visible above the soil line. If the tree trunk looks like a telephone pole with straight sides into the ground – there is problem. While avoiding damage to the trunk, carefully remove excess mulch and soil (often trees are also planted too deeply) to expose the root flare. Further from the trunk, a rake may be used. Cut away roots that may press against the trunk and cause girdling. You may notice an indentation in the trunk from a girdling root. Reinstall no more than one-inch of organic mulch over the rootball. Keep the mulch four inches from the trunk. A How to Excavate a Root Collar and Remove a Mulch Volcano YouTube video summarizes the procedure (https://www.youtube.com/watch?v=7Mdnc83BF2Q). If a professional is employed to remove mulch and soil, they may use an “air knife” which uses compressed air. It blows away the offending materials without damaging the trunk and roots.
When the tree is surrounded by lawn, provide a lightly mulched circle extending about two to three feet out from the trunk. Avoid stone and manufactured tree mat rings/circles. Never pile soil against a tree trunk or over roots to create a planting area.
Mulch volcanoes are deadly, so spread the word and eliminate the cone of silence about their dangers.
Hortus Oasis (FL26000315) in Winter Park is a boutique garden design company specializing in residential, commercial and specialty gardens. Stephen is a registered landscape architect and Kristin is a certified landscape designer. Contact them at Hortus Oasis (FL26000315) in Winter Park is a boutique garden design company specializing in residential, commercial and specialty gardens. Stephen is a registered landscape architect and Kristin is a certified landscape designer. Contact them at 407-622-4886/ firstname.lastname@example.org