Mulch is a workhorse in the garden. It protects plants, warms the soil, and retains moisture. Mulch can be natural or synthetic.
Natural or organic mulch typically comes from plants such as straw, wheat, or pine needles. However, sheep wool is also a wonderful mulch. Natural mulches degrade and become part of the soil.
Synthetic mulches such as plastic and polyethylene are made from fossil-based materials and do not biodegrade. The paper which is considered a synthetic mulch does degrade.
Which Mulch Is Best for You?
Mulch is not always a one size fits all mentality. Some mulches are better for different applications. For example, a nice fluffy mulch of straw is exactly what my tomato’s need, but my melons prefer the warmth of landscaping fabric.
In addition, I want my button bushes out front to look nice, so I choose a bark mulch to go around them. This suppresses weeds but still allows for good air and water circulation.
Based on your geographic area some mulches may be more readily sourced or cost less.
Benefits of Natural Mulches
Decomposes and adds to soil fertility
Improves aeration
Holds moisture in soil
Protects soil and newly planted seedbeds
Living mulches provide a habitat for beneficial insects
Disadvantages of Natural Mulches
Must be replaced on a regular basis
Fresh materials such as wood chips can leach large amounts of nitrogen from the soil as they biodegrade
Types of Natural Mulches
Advantages of Synthetic Mulches
Some such as landscaping fabric is reusable
Warms soil and can help with season extension
Easy to use
Disadvantages of Synthetic Mulches
Doesn’t add nutrients to the soil
Not biodegradable
Made with fossil fuel components
Plastics - Not reusable and a waste disposal issue
Types of Synthetic Mulch
Are Plastic Mulches Allowed in USDA Organic Farming?
Plastics that are petroleum-based are allowed in organic agriculture. They must be only used seasonally and removed during the winter or when a field is not in production.
What is not allowed are polyvinyl chloride (PVC)
Also, if you are using paper as a mulch those glossy ads are not allowed in organic production. The glossy covering and inks contain harmful chemicals.
Can I Get Mulch for Free?
Yes, you can often source free mulch in your area.
Call your local electric company and ask if you can get a load of wood chips dumped on your property. Electric companies trim trees along roadways that are in the way of power lines. The trimmings are sent through a chipper and into a dump truck. Often, they will dump them for you for free if they are trimming in your neighborhood.
You can also call your local municipality center to see if they offer free mulch sources. Wood chips and leaves are often available to residents. You may want to ask how they are sourced to determine if they come from places where chemicals are used in the landscaping.
Drive around farm country and look for rotting round bales of hay you can get for free since they are no longer good for feeding animals. One caution, these old bales often contain lots of weed seeds. One way to kill them is to put some black plastic over the hay to kill any emerging weeds.
Grass clippings and leaves are good free sources of mulch. If you don’t have enough in your yard, ask the neighbors for theirs. Offer to rake leaves for an older or disabled neighbor.
Installing Mulch
Natural mulches are easy to install. If it’s straw just shake it out and spread. You may want to wear a face mask if you have allergies or are sensitive to dust.
Natural mulches should not be right up against the plant. Push them back from the stem just a few inches. Pests such as slugs and cutworms can hide in the straw.
Natural mulches rarely need to be weighted down. However, if you are using plastic or landscaping fabric you will need to secure it to the ground. Otherwise it may blow away.
Stones and old boards can be used to hold down corners and edges. You can also dig a shallow trench along the side, place the edges in the trench and cover with dirt.
In addition, pins made for securing landscaping fabric are easy to find at garden and big box stores.
Living Mulch
A living mulch is one that is alive and growing. You can plant a living mulch in walkways, between vegetable beds, or in areas that are currently not planted.
Living mulches have many advantages. They protect the soil from heavy rain or snow. They may add nutrients to the soil (think clover). In addition, they often produce flowers that attract bees and beneficial insects.
Annual rye, clovers, and vetch are all popular living mulch plants.