Tuesday, July 6, 2021

Say ‘No’ to Mulch Volcanoes

mulch around treesHave you seen a mulch volcano recently? We bet you have! Mulch volcanoes are created when mulch gets piled high against a tree. This traps moisture against the trunk and can lead to decay, pest damage, or even tree death.

Proper mulching is easy, and it doesn’t just lead to healthier trees, it also leads to more money in your pocket because you’ll be buying less mulch. You’ll also save money on future tree care costs by preventing pest damage and rot.

Follow these tips to keep your new tree healthy when mulching:

  • use mulch to cover the ground as far out as the tree’s branches reach,
  • keep the mulch depth to just 2-4 inches, and
  • don’t let it touch the trunk of the tree.

For more information on proper tree planting and care, visit DEC’s website. For everything you’ve ever wondered about mulch – and more! – visit the Cornell Cooperative Extension of Suffolk County website.

Photo of correct mulching is courtesy of Cornell Cooperative Extension of Suffolk County

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Information attributed to NYSDEC is taken from press releases and news announcements from New York State's Department of Environmental Conservation.

7 Responses

  1. mrdale14424 says:

    Why do we have to mulch trees, especially out as far as the branch span is?
    Tees in the forests aren’t mulched and do just fine.
    I mulch the trees in my yard to a diameter of about 2-3 feet with no mulch volcano. I only much those that can be seen from the street or our windows because that’s what the wife wants. I have trees that I don’t mulch at all and grass grows at the base. I can’t see any difference in growth, health, etc. between the mulched ones and those that are not.

    • JT says:

      I agree, I planted around 80 black walnut trees 15 to 20 years ago. Just stuck a spade in the grass to create a gap, put the seedling in and tamped it down. Some of the trees are now 30 feet tall. I always mowed around them leaving the tall grass around the tree where I could not get to. Perhaps there are situations where mulching helps but in my situation, It would not have helped.

      • Boreas says:

        By planting multiple trees, you created a type of a forest, complete with a canopy, and cooperative fungii in the soil which help the trees obtain and share resources with each other. Of course, at first there was no canopy to help keep the soil moist, and this is how many newly planted trees can fail. Mulching is definitely a good idea on new plantings to help the plant establish healthy roots in a bad environment (lawn). But many trees are tougher than others and can still thrive without our intervention.

    • Boreas says:

      Trees in a forest are in forest soil. They are not surrounded by a lawn monoculture. Trees in the middle of a lawn are not in their preferred environment. Grass sucks up a great deal of water that would otherwise get to the trees. Lack of forest canopy also contributes to drying roots due to excess evaporation. This dryness also contributes to a lack of beneficial fungii in the root system that helps feed the tree as well as protect it from other stresses.

      Mulch can help to provide an “imitation” forest soil in an unhealthy environment for a tree. It reduces moisture loss through evaporation. It can also cut down on injury from mowers and weed-whackers. Yet another advantage is it reduces compaction of the roots because you are not mowing over them. .

      The best thing you can do is ditch the grass and let your lawn revert to a mix of native plants that can help support the tree roots by creating healthier soil.

      • JB says:

        Agree, agree, agree. On the issue of fungi: It is hard to overestimate just how easily forest fungi disappear from cleared land and just how long it takes for them to come back. We have 10 acres of regenerated sugar maple/oak/hickory forest that was pastureland 70-100 years ago and the forest fungi have, for the most part, yet to return, mycorrhizal or xylophagous. But on the positive side, many basidiocarps in particular basically only grow on disturbed land. So, in the wildflower fields you do get all sorts of interesting species, to say the least.

      • JT says:

        I think in my situation, it is below a road culvert so whenever it rains, it gets a lot of water distribution over the area. Wish I could stop mowing, but the surrounding woods are full of Oriental Bittersweet, Virginia Creeper and Wild Grape. So by mowing, it keeps the vines out of the yard. What the canopy does do is reduces how often I have to mow. So instead of mowing once a week, it is like every 3 weeks or monthly later in the summer.

        • Boreas says:

          And the older those trees get and the grass gets thinner, try scattering some white clover and/or pollinator wildflower seeds around. You may get to a point where it doesn’t need to be mowed at all, or perhaps every year or two to knock down unwanted saplings.

          But in my case, I just embraced the native vines and focused on killing the invasives. I don’t have any particularly valuable trees though, and I like the looks of vines. Many dead softwood trees from a cycling water table around my property, so vines on standing dead trees don’t bother me much. Critters like them and they look nice in fall.