What is mulch? Mulch is a product used to cover the soil. It is often composed of tree bark, needles, wood, leaves, or grass. Sometimes mulch is made from gravel or pebbles or other inorganic materials such as recycled tires. Spreading mulch over planting beds helps conserve water and provides a beautiful uniform texture and color. Mulch is an essential component of any Florida-Friendly Landscape.
Why Use Mulch?
Mulch not only beautifies a garden, it benefits your plants and soil. Mulch protects plants’ roots from extremes of heat and cold, by creating a buffer between the soil and the air. It keeps soil moist longer after irrigation, giving roots extra time to soak up the water. This saves you water and money.
In areas of deep shade, where turf and ornamentals won't thrive, consider mulch as a Florida-Friendly alternative to leaving the ground bare. Mulch can also be used as an attractive groundcover where it's difficult to mow or irrigate. And mulch doesn't just help your plants: it can add nutrients to the soil as its organic components decompose, increasing soil's fertility and improving its aeration, structure, and drainage. Mulch can even help reduce erosion and protect plants from certain diseases.
Types of Mulch
When selecting a mulch, consider the following characteristics:
- Nutrient Content
Here are some types you can choose from:
Pine bark is a byproduct of the forest industry. It comes in ground and nugget forms and has a rich brown color.
Pine straw (needles) comes from pine plantations, which produce paper and wood products. Unlike some mulches, pine needles are not likely to wash away because they knit together.
Fallen leaves (including grass clippings) can be raked up for free in your landscape. This type of mulch is high in nutrients but decomposes quickly.
Melaleuca mulch is made from the exotic invasive trees. The product is cured at a high temperature to kill the seeds so they won’t germinate in your garden.
Mixed hardwood mulch is produced from scrap lumber, recycled pallets, or tree stems too small for use in paper or wood production.
Eucalyptus mulch typically comes from plantations in South and Central Florida, where the trees are grown specifically for this purpose. They grow quickly, so this mulch is considered renewable.
Utility mulch is sold or given away for free by many utility companies. This mulch comes from trimming trees and other plants that get in the way of power lines; but be aware that it can come with weed seeds.
Cypress mulch is composed of both wood and bark. Cypress trees, which grow in Florida’s forested wetlands, are often harvested for lumber and used in fencing, flooring, furniture, and other products. Cypress mulch is often made from the waste wood generated in the manufacture of these products, but it may also come from whole trees cut from wetlands. The Florida-Friendly Landscaping Program does not recommend the use of cypress mulch, as its origins may be difficult to determine.
Gravel or pebbles can be used as mulch, but they won’t contribute to the soil’s nutrient content or water-holding capacity. If you use this type of mulch, make sure to first install a woven ground cloth to keep it from sinking into sandy soils. This mulch lasts a long time, but it will need to be cleared of debris to look its best.
Using Mulch Wisely
When applying mulch in the home landscape, be sure to follow these simple tips:
- Maintain a 2- to 3-inch layer around established trees, shrubs, and bedding plants. Coarse materials, such as pine nuggets, may be applied to a depth of 4 inches, but don't allow mulch to accumulate to a greater depth. Adding more mulch can harm plants because mulch intercepts rain and irrigation meant for plants' root systems.
- Avoid "volcano mulching." When mulch is piled against the base of a tree, it holds moisture, encouraging rot in the trunk. Mulch piled against the trunks of young trees may also create a habitat for rodents that chew the tender bark, and can ultimately kill the trees.
- Mulch to the drip line or beyond. The mulched area around the tree should be at least 8 feet in diameter. Remember that in a forest a tree's entire root system (which usually extends well beyond the drip line) would naturally be mulched by fallen leaves.
- Rake old mulch. Some mulches can become matted, preventing water and air from seeping through. Rake mulch to refresh its appearance and benefit plantings.