As we’ve discussed before a number of times, mulch is an effective tool that can help you keep your trees healthier and happier. Mulch helps to reduce the evaporation of water and retain soil moisture, it helps to prevent soil compaction and it provides a wealth of organic compounds that help to nourish the tree.
Mulch also looks pretty nice, and it doesn’t cost very much, so there aren’t many reasons to avoid using it. However, there is one important thing to consider when using mulch: fire safety. Improperly stored or maintained mulch can spontaneously combust, and many mulches can catch fire if an ember drops out of the sky during a wildfire.
Mulch fires can also cause trees to catch fire, which can set up a potentially disastrous scenario. Accordingly, it is important to select, store, monitor and spread mulch properly. Just follow the three tips below to help prevent your mulch from causing problems.
1. Choose One of the Safest Mulches Available
Some mulches are 100% safe in the case of a fire, some are quite flammable and are very likely to combust in a serious fire, and others fall in between these two extremes. For example, gravel or crushed rock won’t catch fire unless you chuck it into a volcano, but pine straw or shredded cedar mulches may combust if you look at them the wrong way. And some mulches – such as shredded tires – may seem fire-safe, but they are actually highly flammable and burn at hotter temperatures than other mulches.
Composted wood chips are one of the best choices. They are the most fire resistant of the major mulches used by landscapers and tree-care professionals, and they do not cost much more than other, comparable products do.
2. Store and Monitor Bulk Mulch Properly
Once you’ve selected your mulch, you must be sure to store it in a sensible manner. Additionally, because large piles of mulch can spontaneously combust thanks to the heat that builds up in their cores, you must monitor them frequently to watch for signs of heat buildup.
Proper storage generally means limiting the size (height) of the pile as much as is possible and placing it in an area sheltered from the sun. This will reduce the amount of heat that builds up inside the pile and prevent the rapid evaporation that sunlight can cause. It is also important that you avoid placing large quantities of mulch in close proximity to homes to help mitigate the damage caused in the event of a fire.
Once you’ve piled the mulch in a safe place, you must check it frequently to ensure it isn’t smoldering or displaying signs that it may do so. Many professionals do this by looking for hot spots with the help of a temperature probe. If you find that some portions of the pile are becoming too hot, you’ll need to take steps to remedy the situation.
Among other things, you can ensure that the mulch pile is adequately moist – many authorities recommend keeping the moisture level at 50% to prevent combustion. You can also turn the pile frequently, to help allow the heat generated inside to dissipate.
3. Spread Mulch Properly
It is important to spread mulch in a relatively thin layer around the base of your trees to help prevent heat from building up. Typically, a 2- to 10-centimeter-thick layer is ideal; fortunately, this is also an appropriate quantity from the tree’s point of view as well. You’ll also want to avoid using flammable mulches near your home or driveway (although gravel and other inorganic materials are still acceptable).
Additionally, while dead trees represent a significant fire hazard, and it is always important to have them removed as promptly as is possible, it is even more important to remove any mulch surrounding them at the earliest possible opportunity. If this mulch were to catch fire, it could easily cause the entire tree to go up in flames.
If you need help mulching your trees, or you need to purchase some mulch of your own, give your friends at Trav’s Tree Service a call. We’ll be happy to help address your mulch-related needs, so you can keep your trees looking their best. Mulch is most important in the summertime, but you should keep your tree’s roots covered all year long, and you can apply it at any time.