Is it okay to be using oak tree leaves for mulch? Absolutely!
January through March is the time of year when we start to see oak tree leaves everywhere. I mean everywhere. We are very fortunate to live in an old part of Orlando that is graced with many old Southern Live Oaks in the neighborhoods. Most of the year they are nothing but a treat to have around. They provide shade as well as add to the character of our old neighborhood. And then there is the six weeks or so of the year when they drop leaves continuously.
I spent some time this morning raking up the oak tree leaves from our street and sidewalk. This serves two purposes: it looks much cleaner and the oak leaves are an excellent free mulch. I am not a person to pass up free, so these leaves are a welcome addition to our yard and garden. For me this seems much more reasonable than going to the home improvement store and spending money on mulch while adding these to our increasing landfills.
For some reason most people seem unwilling to use oak tree leaves for mulch. I see bags and bags of these lined up along the street (and yes, I am that person that sneaks out under the cover of darkness to nab this “trash” and use it in my yard!). There is the notion that adding oak tree leaves will turn soil acidic as the leaves decompose. Do not believe this. Most soil in central Florida has neutral soil pH of 7.0. As an extension agent we did many of these soil tests and it was very unusual to see anything outside of the 6.5-7.5 range. If anything, slightly acidifying our neutral soil would be good for most plants. Changing the pH of soil is very difficult and even a slightly acidic addition will be buffered by the soil’s natural pH and show little to no effect.
As the oak leaves decompose they will add organic matter to your soil that helps to increase the water holding capacity (i.e. fewer wilted plants) and nutrients available. The University of Florida writes about the importance of organic matter: Regular additions of organic residues are needed to maintain a consistent amount of organic matter in soils. In a natural ecosystem, this addition is achieved by the constant recycling of organic matter as plants and animals leave residues or die. In an urban landscape, this cycle is often disrupted when plant trimmings and residues are removed and sent to the landfill.
These leaves are a great resource, why would you ever consider throwing them out?
I take my large rake out to the street and rake the oak tree leaves into large piles. Once this is done I scoop them up on the rake and take them to the areas that need some extra attention. If there is moss, small sticks or some debris in with the leaves I don’t worry about it too much. They will break down over time as well. Spread the leaves out under and around your plants. You can see here that I really just dump them under the shrubs and kick them around a little to disperse. If you don’t like the way that leaves look, you can consider sprinkling some purchased mulch on top of the leaves. To get the most benefit from mulch it should be 2-3″ in depth. You can do this solely with oak leaves or you can add other mulches to achieve this depth.
This season, embrace your oak tree leaves (or your neighbor’s!). Consider those bags of leaves by the road a prepackaged present just for you! Using oak tree leaves for mulch will help your landscape to grow beautifully, keep waste out of the landfill and build good soil for years to come.