There was a thread on reddit about it and from preliminary studies, they couldn’t find evidence it was as bad as made out to be.
Yeah, looks like shit, has risks and obviously no risk is better, but I find interesting that sometimes a short study reveals results opposite to what you can imagine.
Here is summary:
- The document discusses the characteristics and effects of fungi on woody plants and trees, including cankers, root rots, wood staining, and seedling blights.
- The majority of the fungi isolates are likely to be saprophytes, which are not extensively studied as pathogenic fungi.
- The document mentions the identification of 83 isolates using DNA extraction and sequencing.
- The study found no aggressive pathogens on the trees in urban landscapes that were tested.
- The document also discusses the potential role of volcano mulching in promoting disease on tree trunks, but notes that this has not been confirmed by research.
Here is document:
Here is thread. Comments are worth reading. BEWARE reddit:
https://old. reddit.com/r/arborists/comments/xld41f/regarding_the_epic_volcano_mulch_discussion/
You know I think there is a much bigger problem with this mulching that wasn’t addressed: hydrophobic mulch. When you pile it on that thick it can become hydrophobic where it forms a waxy layer on top that water can’t even penetrate. Bark mulch shouldn’t be any thicker than 1-2”. Straw, manure, compost can be thicker but that looks like bark mulch in the video to me
Aren’t there issues with girdling roots as well?
Interesting point, but I largely agree with the top comments in that thread—this study doesn’t constitute strong enough evidence to demonstrate much definitively. It certainly suggests a need for further research.
Personally I have had questions about the conventional mulching methods. Many arborists insist that there must be a lot of space between the mulch and the trunk—I’ve sometimes seen as much as 6 inches recommended. My concern is that for a small tree, this constitutes most of the root ball, and you may be giving up on much of the benefits of mulch if you follow these instructions.
Additionally, if there is a big space against the trunk, it creates space for weeds to grow. In a well maintained tree this is a minor issue—simply remove them by hand. But most trees are non well maintained, and many landscapers will use a weed-whacker to solve this problem, which is far more dangerous to a young tree than a bit of excess mulch. In my experience, this type of lawn equipment damage is one of the most common causes of death in young trees.
Yeah, definitely. I hope no one thinks I’m advocating for mulch volcanoes. I just remembered the thread and I’ve seen a lot of them. You have to wonder when you see some that are decades old, maybe it’s not as bad as we think.
Problem with being in the internet is that the US users tend to drown out everyone else. So if US posters don’t like pollard or coppice, or mulch volcanoes, or coronet pruning, then anyone who suggests differently is downvoted heavily. Coppice and Pollard are a good example as it’s common in Europe/UK, a very old practice with fairly solid arboricutural fundamentals, but Americans tend to hate it.
A classic one is the obsession with planting at the flare. Like @[email protected] mentions about girdling roots, there is a common planting dryland technique used in Australia that flies in the face of flare planting called long-stem. Mention that planting at the flare isn’t necessary for different species due to adventitious roots and the downvotes begin. Long-stem and mulch volcanoes have some things in common, trees in riparian zones with flood debris also have it so there is a natural process of mulch volcanoes that doesn’t kill them. @[email protected]’s comment about hydrophobic mulch is a good one.
About long-stem:
The long-stem planting method is a technique used for planting seedlings with longer stems than usual. The method involves burying the root ball of the seedling deeply, so that the stem is also buried. New roots sprout from the leaf nodes along the buried woody stem, which enhances the survival rate of the seedling with minimal post-planting care[1][2][3]. This technique is effective in environmental restoration projects around Australia, and tens of thousands of long-stem plantings have been highly successful over the past fifteen years[4]. Plants that are most likely to succeed with the long-stem technique are those that are successful by stem cuttings, and even some woody plants can be planted using this method[5][6]. The advantages of this technique over the conventional planting method include insulating the root ball from environmental stresses such as temperature extremes and drought[4].
Citations: [1] https://site.emrprojectsummaries.org/2011/12/06/planting-for-success-using-long-stem-plants/ [2] https://www.environment.nsw.gov.au/resources/grants/longstemguide.pdf [3] https://www.tintuppanursery.com.au/long-stem-planting.html [4] https://www.abc.net.au/gardening/how-to/long-stem-planting/9430210 [5] https://www.gardeningwithangus.com.au/deep-long-stem-planting-better-plant-establishment-in-the-garden/ [6] https://www.nrcs.usda.gov/plantmaterials/nmpmcbr7106.pdf
In regards to whippersnippers, yep! I would have loved to have done some statistical analysis if records were kept on tree mortality as soon as whippersnippers were common and affordable. I think trees in common road frontages took a terrible turn for the worse at that point. A lot of plantings in Aus now have sleeves because of that.
