Mulching for Microorganisms
What is Mulch?
We have all heard someone talking about mulch when it comes to taking care of plants.
“Mulch your plants.”
“Lay down mulch.”
”It just needs some mulch.”
When it comes down to it, do we truly know the different kinds available, the benefits of each along with their costs?
According to Wikipedia, “A mulch is a layer of material applied to the surface of soil. Reasons for applying mulch include conservation of soil moisture, improving fertility and health of the soil, reducing weed growth and enhancing the visual appeal of the area. A mulch is usually, but not exclusively, organic in nature.”
This means that any formerly living material that is capable of absorbing water and providing nutrients back to the soil that can also suppress weeds is a mulch. By looking at what is readily available around us, we can find many materials that are organic in nature that fit these criteria.
Types of Mulch
Most of the time when we think of mulch, images of pine straw, wood mulch, or wood chips comes to mind. While these two are the most commonly used mulch, they are often the most expensive. Other types of mulch are chopped leaves, straw, grass clippings, compost, shredded bark, sawdust, and even paper and cardboard.
Many of these materials are readily available on the home property and can add insoluble nutrients. Remember that microorganisms need a 30:1 carbon:nitrogen ratio in order to survive. Feeding microorganisms with insoluble food is the equivalent to feeding a diabetic with slow release sugars. Microorganisms will not experience a spike in population with a quick boost of food before dying off from the lack of other resources. Over time, as the microorganism population grows, so does its ability to care for the plants in the garden. Each comes with a unique task, such as transferring nutrients or secreting antibiotics into the soil.
Below I will go into three of the most common mulches that can be found on the home property. While I do not discuss the others, this does not make them any less important. Most of the other mulches can all be acquired free as well, sometimes a little extra effort and communication is required to find them. Is there a local farm nearby willing to give away straw, or a mill that has sawdust to give? Make sure whatever material you acquire is non treated.
Grass
Grass clippings can be easily saved when you mow. Lay down on top of your garden bed and the nitrogen from the drying grass will seep into your garden. Grass that has been treated chemically is not recommended to use as a mulch. The chemical fertilizers from the grass can seep into the garden, throwing off the nutrients within, effecting the growth of the plants.
Cardboard
Cardboard is a great weed barrier and an excellent source of carbon to the garden. If you are looking for a natural way to prevent those pesky weeds, this is it. Save up all of the boxes you receive from Amazon, Sam’s Club, or anywhere else and lay down as a base layer in your garden or around your plants. Within a few months, the cardboard will have broken down, creating a home for new microorganisms and killing the weeds at the same time.
Leaves
When fall comes in North Florida, we get the beauty of having some of our trees lose their leaves, and many keep them. Often, when our trees lose their leaves, we find ourselves outside raking & bagging up the leaves, or calling a landscape company to rake and bag them for us. What we sometimes forget is that we are raking and bagging up pounds worth of nutrients that the trees have created for themselves.
Mother Nature works in an interesting way, and with or without us, her goal is to recycle everything on this Earth. So each leaf that falls off a tree has a purpose in its life; to breakdown and provide whatever nutrients is has back into the soil.
With that in mind, each fall we can look at our fallen leaves as a gift of gold for our plants. So instead of bagging it, maybe we rake a portion around the tree trunk where we do not want any grass or weeds, and then we take a good portion and lay down a 2” layer in the fall garden we just planted. Maybe if we have some left, we throw it in our compost bin to create fresh dirt for our potted spring plants. So many ideas abound with all of these nutrients we normally just throw away and allow to rot.
Sheet Mulching
This is the epitome of mulching. Sheet mulching is layering different kinds of mulch that break down together over a period of months to form a mulch that helps to conserve water, suppress weeds, and create soil life. By using a variety of different kinds of mulches, you can help to ensure a good C:N ratio that provides diverse food for microorganisms to flourish. This in turn will provide more diverse microorganisms that can better help the health of your plants and the soil.
Gaia’s Garden, Pg 87.
”The ultimate sheet mulch. Sheet mulch can be as simple as a cardboard topped with a foot of straw, or it can be a more elaborate stack of soil-building layers, as shown here.”
The above image is Toby Hemenway’s Bomb-Proof Sheet Mulch. Not all sheet mulch has to be this elaborate from the get-go though. Feel free to start small and build up over a few years. Keep in mind that doing this may result in some weeds popping up sporadically, especially when the cardboard breaks down and the layer on top hasn’t reached a good thickness.
Yet, do not get discouraged. Add to your garden whenever you can. When you trim your bushes in spring, summer, or fall, take those cuttings and let them break down in the garden. For the quickest breakdown, cut into as many small pieces as possible, and eliminate big branches. See how long you can go without spraying your yard with any chemicals and add a bag or two of grass clippings each time you mow. Before you know it, your garden bed will be much higher than before and better capable of combating what comes its way.
Conclusion
However you mulch, do not forget the important C:N ratio, 30:1. Below is a table that shows different mulches and compost materials that can be used to create healthy soil life. Again, many of these can be found for free within the community. If you do not have animal manure (not dog or cat!), a friend you know or a vendor at the market may have more than enough chicken manure to share.
Left
Gaia’s Garden, Pg, 80.
The combination of these different materials will be what helps you to create the balanced diet needed for microorganisms to thrive