It was once thought that you should not add oak leaves to your compost pile or use in your garden. It was claimed they were too toxic because of the tannins and they were too acidic. These are myths; our oak leaves are too beneficial to bag and toss!
Most tree leaves can be composted. Live oak leaves and pecan leaves are among those that can and should be composted. The few leaves that should not be composted fall into two groups: 1) beech, holly, and sweet chestnut because they are higher in lignin and lower in nitrogen and calcium, and 2) black walnut and eucalyptus because the leaves contain natural herbicides that will prevent seeds from germinating. Beech, sweet chestnut, and black walnut trees are not common here.
Leaves improve the soil by adding a wide range of nutrients and organic matter. Organic matter improves the structure of the soil, whether it is sand, heavy clay, or a combination.
The first thing that you will need to compost leaves is patience. Live oaks drop most of their dead leaves in the spring, but they do fall all year long; you will need the patience to get the last leaves. Leaves, especially oak leaves, can be tougher than cardboard and will take longer to decompose; you will need patience for them to break down.
You can reduce the time it takes the leaves to decompose by chopping them into smaller pieces; this allows the microbes greater access to the internal structures of the leaf – much like a two-year-old will make cut-up pancakes disappear faster than whole pancakes, but for somewhat different reasons.
There are various ways to compost leaves. My favorite way to compost live oak leaves is to mow, mow, and mow – via a riding lawn mower! The reason for mowing the leaves three times is to chop them into the tiniest pieces. I generally leave the clippings in place to deteriorate where they land. This adds organic matter to my 99.9% sandy soil.
My second favorite method is to mow, mow, and then blow them into piles that are easier to pick up. I then move the clippings to my vegetable garden and use them as mulch around the plants, like around my Cherokee tomatoes or zucchinis. At the end of the spring or fall garden, they are composted well enough to mix into the soil just before the next planting.
The shredded leaf pieces also can be added to compost piles or to vermicomposting bins for worms to eat. Add the shredded leaves to your compost with equal amounts of green matter. Leaves for worms will need to be damp; do not overfeed your worms.
A past practice of mine was to mow, mow, and then bag the leaves. I would place the bags behind the house and in the sun. Within a year, I would open the bag to find a lumpy soil ready to be added to any garden.
A favorite method of dealing with leaves of some is to blow the leaves. Some blow them off the property into the street and others bag the leaves. The bags are put out by the street for the city or trash haulers to pick up. The leaves blown into the streets (which is not allowed by most city ordinances) may make their way to drainage systems or bodies of water. Instead of blowing the leaves, vacuum the leaves and add them to your compost pile or bag them and save them for next year.
My unfavorite method is to rake the leaves. Sometimes this is necessary for areas where a lawnmower cannot get. Raking will not chop the leaves into smaller pieces. You may bag whole leaves but will need to be additionally patient for their breakdown. When the black garbage bag is breaking down on its own, the leaves are probably ready to be used in your garden.
Save those leaves! Do not let them be hauled away!