Gardening is an ancient activity that has been around for a long time.
And of course, there are a few myths, old wives’ tales, and half-truths about how to compost different materials.
Composting with oak leaves is one topic that produces endless debate among gardeners.
But what is conjecture, and what is the truth about using oak leaves in your compost?
I’ll tell you everything you need to know about composting oak leaves below.
Can You Compost Oak Leaves?
Oak leaves can be used in composting if treated in the right way. Gardening legends say oak leaves are toxic and acidic due to their high levels of tannins. This is only partly true. If you use oak leaves the right way, your compost will have no problems.
Oak leaves have high levels of tannins.
This is what led to the idea that oak leaves are not suitable for compost, resulting in two fears:
- Oak leaves are acidic: People fear that oak leaves will impart acidity to the compost and that this will kill beneficial microbes and critters in the compost pile. This would effectively halt decomposition. The resulting compost will be too acidic and harmful to your garden plants.
- Oak leaves are toxic: Gardeners believe high tannin levels in the leaves are poisonous. They fear introducing these toxins into the compost and soil, damaging your garden plants.
Like with most myths and legends, the negative reputation of oak leaves has a smattering of truth.
But is it essential to avoid certain varieties of leaves for compost?
If you have an abundant supply of oak leaves in your garden, passing up such a fantastic resource for your composting operation would seem a shame.
In truth, you CAN use this rich resource to benefit your compost as long as you do it in the right way.
And it is easier than you think!
Are Oak Leaves Bad For Compost?
While it is true that oak leaves have a higher level of tannins than other trees, this does not translate to toxicity for a compost pile.
There are not many insects or other critters that eat the leaves of oak trees. People believe this is because the leaves are toxic, so creatures avoid them as a food source.
The reason animals avoid leaves with high tannin levels is due to taste, not toxicity.
Tannins impart a bitter taste to the leaves, which the animals and other creatures don’t like. Also, for insects, tannins prevent them from digesting leaf material correctly.
But tannins are present in many foods and beverages we consume and are not harmful.
Oak leaves are not toxic and will not be harmful to your compost pile’s microbes and the micro-environment. They will also not impart any dangerous characteristics to the finished compost.
The biggest problem with oak leaves for compost piles is that the leaf structure is robust, making them tough to break down.
The additional time they take to decompose is sometimes mistakenly attributed to the leaves killing off the microbes that rot the organic matter in the compost pile.
Are Oak Leaves Too Acidic For Compost?
Oak leaves are more acidic than many other leaf types, but not to the extent that they can be a problem in your compost pile.
This is another aspect where there is some truth to the legends about oak leaves.
Green oak leaves have a pH value of between 4.5 and 4.7, which puts them on the acidic side of the scale. But the acidity in the leaves quickly breaks down once the leaves fall from the trees and begin to decompose.
(Most finished leaf compost starts out acid and becomes more alkaline, with a reasonably neutral end product – pH between 6 and 8)
Studies of the soil around the base of oak trees have revealed that even after years of leaves falling at the tree’s base, the earth is no more acidic than the surrounding soil.
The acidity in oak leaves neutralizes quickly when the leaves fall from the tree.
By the time the leaves have decomposed, they do not affect the soil’s acidity or the resulting compost.
Consequently, the notion that oak leaves are too acidic for a compost pile is a gardening myth that can be safely ignored.
So you can safely throw your oak leaves in your compost pile!
Can You Compost Live Oak Leaves?
Live oak trees are a species of oak trees that flourish in the southern United States. These trees are considered evergreen trees, but they are not genuinely evergreen since they drop their old leaves as the new leaf growth begins.
In contrast to other oak trees that lose their leaves in the fall in preparation for winter, live oak trees lose their old leaves in the spring when the new leaf growth cycle begins.
Other than the time difference when the leaves are dropped, live oak leaves are no different from other oak leaves and can be utilized in the same way.
How To Compost Oak Leaves
One of the challenges of using oak leaves in your compost is the time it takes for the leaves to break down. Oak leaves are tough and leathery on the tree, and the fallen leaves are robust, making them difficult to decompose.
How Long Do Oak Leaves Take To Compost?
Freshly fallen oak leaves take a long time to decompose, which is why they are not a popular addition to compost piles.
Oak leaves in their natural state can take from six months up to a year to fully decompose in the compost pile, depending on the method being used to compost.
However, it is worth putting in a little extra effort with your oak leaves to include them in your composting rather than losing the valuable resource.
How Do You Make Oak Leaves Compost Faster
Oak leaves are generally slow to decompose, but you can make the process go quicker by processing the leaves first.
The best action to improve oak leaf decomposition time is to chop up the leaves into smaller pieces.
This helps the microbes gain access to the internal structures of the leaf. At the same time, you increase the surface area of the materials, meaning that more of the material is exposed to the composting microbes. This allows them to work faster on the oak leaves.
How To Shred Oak Leaves
There are a couple of easy ways to shred oak leaves.
One of the easiest methods is to use a lawnmower. Just run over the leaves a few times to grind them into smaller particles.
It helps if you have a lawnmower with a mulching blade (like this one – Amazon).
Rake the leaves into a pile so that they are in one small area before running the lawnmower over the pile. This will make it easier to collect the smaller pieces if your mower does not have a collection device.
Another option is to use a leaf vacuum with a mulching option.
Leaf blowers with this mulching function can chop the leaves up to 1/16 of their original size and have a collection bag to contain the small chunks.
Less strain on your back!
The mulched leaves can then be added to your compost pile, and they will rot much faster!
Finally, a garden shredder like this one is ideal for grinding up large quantities of leaves. (Amazon)
The advantage of a machine like this is that it will also deal with twigs, branches, and other yard trimmings.
Composting Oak Leaves With Worms
Many gardeners use vermicomposting to produce rich, organic compost for use in their gardens. But given the rugged reputation of oak leaves, can you use these leaves if you are composting with worms?
Oak leaves can be used for composting with worms. However, the worms will be able to better process the leaves if they are shredded before adding them to your vermicomposting bins. (Amazon)
Guidelines For Composting Oak Leaves
Use the following guidelines to get the best out of your oak leaves and produce nutrient-rich compost faster:
- Shred the oak leaves prior to composting.
- Hot composting will break the leaves down quicker.
- Vermicomposting is another fast method to compost oak leaves, provided they are shredded first.
- Cold compost if you are willing to wait up to six months for the compost to be fully decomposed. You can also compost in bags and make leaf mold.
If you have oak trees in your garden, you should view the oak leaves as a blessing rather than a curse. Change your tactics and turn the fallen leaves into a valuable nutrient-dense resource for your garden by composting your oak leaves!