General Guidelines on How to Apply Mulch
Weed Before You Mulch
Always remove perennial weeds like docks, dandelions, plantains, and grasses before you mulch. Treating with a weed-killing chemical is an additional option, in conjunction with pulling the weeds.
Mulch should be applied to a weed-free soil surface. Simply covering perennial weeds such as Bermuda grass or nutsedge will not prevent their growth.
Depth of Mulch
A 2 to 4-inch layer of mulch (after settling) is adequate to prevent most weed seeds from germinating. The mulched area should include as much of the root zone as possible. For beds, mulch the entire area. For individual plants, such as trees, the mulched area should extend at least 3 to 6 feet out from the base of the plant. It is advisable to pull the mulch 1 to 2 inches from the base of plants to prevent bark decay.
Mulch depth depends on the type of material used and the drainage and moisture holding capacity of the soil. How thick you apply mulch depends on both personal preference, as well as the size of the nuggets or individual pieces of mulch that you’ve selected (i.e. bark, shredded, chips, etc.).
Thin, fine particles like compost or finely shredded bark are best laid only 2 inches (5.1 cm) to no more than 3 inches (7.6 cm) deep around most plants and trees. If you put down a thicker layer than that, you risk reducing oxygen to the roots. Sandy soils dry out quickly and often benefit from a slightly deeper mulch layer (3 to 4 inches).If the particle size of your mulch is larger, like straw, pine needles, chunks of bark, or rock, they can be applied up to 4 inches (10 cm) deep. The larger spaces between the chunks allow more air and light in, so you will need a thicker layer for effective weed control, water conservation, and protection from cold.
When applying any kind of mulch, be careful to leave some space (i.e. a moat effect) around the plant crown, or tree base. If you pile any kind of mulch up against the crown, you will choke the plant out and it will most likely die. Therefore, leave 1 to 2 inches (2.5 to 5.1 cm) of ‘breathing room’ near the stem or base of the plant.
When to Apply Mulch
Mulch can be applied any time of the year; However, the best time to mulch is late spring after the soil has warmed. Early spring application will delay soil warming and possibly plant growth. It is not necessary to remove the mulch when you fertilize. Apply the fertilizer over the mulch — nutrients will move with water to the roots below. Mulch typically needs replenishing, at least, two times a year (once in the Spring and once in the Fall).
You will need to replenish, not replace, any mulch over a period of time, and this is based on your personal preference depending on the appearance you want in your beds. Once you have a 2 to 3-inch base of mulch, you would then only need to add a thin layer on each future installation.
Mulch and Mother Nature
Mulching also has a tendency to attract earthworms, which are often good indicators of soil health. An earthworm casting, which is a nice way of referring to the solid waste of the worm, has countless benefits to the soil. Castings act as a fertilizer and can increase a plant’s ability to absorb nutrients from the soil. The castings also contain bacteria and microorganisms that, just like the worms, help break down organic matter. As organisms break down the mulch, it will help provide additional nutrients to the soil. By working with nature’s inherent chemistry you can forgo and/or supplement the expenses of using chemical fertilizers.
Will mulch attract termites or bugs?
No. Bark mulches are not an attractive food source for termites. Termites prefer large pieces of wood typically 6-inches or larger. Termites can only live in moist areas or where there is a nearby water source. The best preventative steps to protect your home from termites is make sure water properly drains away form the foundation and have your home inspected and treated annually by a licensed exterminator.
After You’ve Mulched
Be sure to water your plants. Overall, the healthiest plants are those that have access to a consistent supply of water and nutrients, and mulch helps with this. As mulch breaks-down, and when watered or rained on, mulch provides nutrients to the roots, earthworms, and soil organisms. This is why many plants have their feeding roots right under the soil surface, so they can easily grab the food as it becomes available to them.
What is, “mulch”?
Mulch is, by most definitions, a protective covering that is spread or left on the ground to reduce evaporation, maintain even soil temperature, prevent erosion, control weeds, and enrich the soil.
Mulching is one of the easiest, most beneficial tools you can use in the yard or garden. Mulch is an inexpensive, protective layer of material (this could be shredded tree bark, pine needles, rubber mulch, rocks, wood chips, etc.) that is spread on top of the soil. Mulch can be used for entire garden ‘beds’, borders around homes and structures, and around individual trees, shrubs, annuals, and perennials. Mulching is an important practice for establishing new plantings, as well maintaining the health of older, established ones. In addition to being useful around plants, mulch can also be used as a general ground cover for walks, trails and play areas.
How does Mulch work?
•Controls weeds - adding a thick base (3-4 inches) around your plants, shrubs and trees, will deter weeds from growing.
•Increases moisture retention - this means less watering during the summer, which, in turn equals water conservation!
•Regulates temperature- mulch keeps plants cool in the summer and warm in the winter. It helps to regulate soil temperature and insulate your plants, trees and shrubs.
•Protects barren soil from taking a beating from sunlight- prevents a hot, dry root environment.
•Reduces soil erosion- defends the top layer of soil from hard rains and wind.
•Makes mowing easier-A ring of mulch around your trees and shrubs makes mowing a lot easier; allowing you to mow right up to the edge of the mulch. Mulch around tress/shrubs also protects surface roots from damage by mowing equipment.
•Enhances curb appeal- Mulch is offered in a variety of colors, size and textures to fit all types of landscape requirements and personal preferences and enhances the appearance of the property.
• Provides a “finished” look- richens your property’s attractiveness.
• Adds nutrients to the current soil- Over a period of time, mulch will break down into a dark, rich soil, which will enrich your existing soil and add organics back into the ground. This will provide a much healthier environment for your plants, trees and shrubs.
Wind Can Work Against You
One downside is that the war against weeds is never over, and while mulch helps a lot, nothing can prevent wind-borne seeds from germinating on top of a mulched area.
The really good news is that when you have a nice layer of mulch, it makes it much easier to get rid of small weed because a light stirring with a cultivator or hoe will kill them with little effort on your part.
The ideal mulch is:
Suitable to your climate and geographical location
Easy to install
A product that will stay in place
A good supplier of organic matter to the soil
Free of noxious weeds, insects, and diseases