Is it okay to use leaves as mulch?
Leaves are a great source and can be placed straight onto your garden delivering nutrients back from the first moment they get wet. Leaves won’t stop delivering nutrients until they have 100% broken down.
Leaves deliver a whole range of nutrients. Think of a cup of tea, you pour water over tea leaves, and within a few moments, you have a beautiful cup of flavoured tea that smells and tastes delicious.
Leaves serve the same role for plants. Trees drop leaves when temperatures are low or high. In the case of deciduous trees, leaves fall as winter signals that its time for trees to go dormant. For Eucalypt trees, it is a different story. As summer hits its peak and water sources aren’t high enough, leaves fall. If summers are too long, whole branches are dropped by trees delivering material to the ground.
Now let’s go back to that cup of tea. If you place leaves in water, they release their nutrients into the water. In fact, leaves release 50% of their nutrients in the first 24 hours they are in the water. By wetting your leaves where they are first placed you get instant and free fertiliser!
Nature is clever. The role of leaves is to store nutrients. In any natural area leaves take the nutrients back to the ground and they deliver the organic matter that soils need to be healthy. Some nutrients remain stored in the leaf until it finally breaks down, and other nutrients are released as soon as leaves get wet for the first time.
Get Growing’s Horticulturalist Tim Edmonson fertilises his grass with Oak leaves. You can see a demonstration here. First, he waters the leaves, then he mows them, and then he repeats. This process is repeated until the leaves are little cornflake sized particles left on his lawn. You could do this and then place the leaves onto any garden bed delivering a thick layer of mulch that stops weeds from growing and keeps water in your garden bed.