Mulch

Applying mulch is one of the best things you can do for your flower and plant beds, trees and vegetable garden. Mulch is a layer of organic or inorganic material that is spread out on top of the soil to protect against erosion and conserve moisture. Both organic and inorganic mulches have many benefits, although organic mulch actually enriches the soil. Mulch helps plants maintain a more even soil temperature and prevents weed growth to reduce garden maintenance. In addition, mulch gives your garden beds a neat, landscaped appearance. Before you buy mulch, consider the following questions:

• Are you looking for a way to reduce weed growth?
• Does your garden need mulch that will improve the soil?
• When is it appropriate to use landscape fabric as mulch?
• How much wood mulch should you apply for best results?
• How long do you want your mulch to last? 

How much garden soil / mulch do I need?

Garden soils and mulches should be applied at a 3" depth. Therefore, six 1 cubic foot bags will cover 24 square feet. 

 

Organic Mulch, Inorganic Mulch and Application

There are two basic types of mulch, organic and inorganic. Both act as ground cover and offer the benefits of insulating and retaining soil. Organic mulches break down after a season or two and need to be reapplied. In this way, they actually enhance the soil by adding organic material. Inorganic mulches are more permanent, but they do not improve the soil structure. Other types of mulch vary according to their appearance and longevity. Before you add mulch to your garden, you'll want to take a few minutes to learn about how much you should apply, both for the benefit of your plants and to prevent yourself from buying too much or too little material.

 

Organic Mulch: Many organic mulch materials can be found in your own yard, such as grass clippings, leaves and pine needles. Newspaper is excellent mulch for vegetable gardens, as it keeps weed growth down and protects low-hanging vegetables. Composted manure is also excellent for vegetable gardens but will not work for front yard gardens for obvious reasons. Hay and straw work well, especially when you need mulch that is light and airy, such as a lawn cover after applying grass seed. There are also several attractive wood mulches that can be purchased.

• Organic mulch fertilizes sandy soil and helps hold water and nutrients
• Bark mulch lasts for one to three years, then may require reapplication
• Smaller wood chips are easier to spread around smaller plants
• Be aware that hay and straw mulch may harbor weed seeds
• Pine needles increase soil acidity, making them ideal for use around acid-loving plants

 

Inorganic Mulch: Inorganic mulch includes stone, landscape fabric and plastic. Though these materials are not as beneficial to the soil as organic mulch, they last much longer. Black plastic does not work well in landscaping but may be useful in a vegetable garden. Landscape fabric is applied to the surface of soil before planting and is porous so it allows water in but keeps weeds out. Stone is used on paths, around walkways and around permanent plantings, such as shrubs and trees. Stone does not work well for vegetable or flower gardens.

• Black plastic is best used in areas where drainage is good as it retains water
• Do not use landscape fabric for plants and flowers that spread as they grow
• Cover landscape fabric with decorative mulch to enhance its appearance
• Do not use stone around acid-loving plants as it may add alkalinity to soil
• Stone mulch reflects heat in summer, so locate plants accordingly

 

Application: To learn more about how to apply different types of mulch for maximum effectiveness, consult the following chart.

 

Mulch Type	Application Tips
Bark	Apply 2" to 4" of bark mulch around plants Keep bark mulch an inch or two away from tree trunks
Black Plastic	Prepare soil by raking until smooth Wet ground lightly -- do not lay plastic on dry soil Lay plastic where needed Plastic should be in close contact with the soil for maximum heat transfer into the soil Secure edges of the plastic with soil or rocks Lay black plastic down in a vegetable garden two weeks before planting to allow sun to heat the soil When planting time arrives, cut the plastic for planting and make sure water can reach the soil
Decorative stone	First mark off the area you intend to fill, then line with edging material to form a sharp border Remove unwanted vegetation Rake to achieve a smooth, even surface Spray the area with weed killer and lay in a layer of landscape fabric to discourage weed growth Top with decorative stone
Grass Clippings	Apply 2" to 3" of clippings Add more layers as clippings decompose Do not use grass from lawns treated with weed killers Spread clippings immediately to prevent rotting
Landscape Fabric	Clear area of existing weeds Install fabric after planting so you can fit the fabric around plants Anchor fabric with metal pins, leaving at least a 6" overlap between pieces Cover landscape fabric with mulch, if desired
Leaves	Chop leaves with lawnmower or shredder before spreading Spread 3" to 4" of damp leaves or 6" of dry leaves Add more layers as leaves decompose
Manure	Apply 3" to 4" of manure Rake into soil before planting
Newspaper	Apply 1/4" of newspaper sheets (3 to 4 sheets) and anchor down with grass clippings or soil Use only black ink pages, as color ink may harm soil and plants Do not apply on a windy day

 

Features 

Black Plastic: Black polyethylene plastic is effective at preventing weed growth, though it tends to hold water in the soil. Some black plastic is sold with tiny holes to facilitate drainage. Exposed to sun, black plastic can degrade and lose it effectiveness, which is why some gardeners bury it in the soil. Black plastic acts as a good underlayment for organic or rock mulches.

 

Decorative Rock: There are many shapes, colors and types of decorative rock that can be used as mulch, including pea gravel, pebbles, crushed stone, river rock and more. Stones used for mulch are usually smaller and are well suited for foundation plants. Decorative rock provides excellent weed control and does not need to be replaced unless the layers settle after a few years.

 

Landscape Fabric: Landscape fabric is sold in a range of widths and lengths and is specially treated to resist rotting. Unlike plastic, landscape fabric is porous and allows water, air and nutrients to pass through. Weeds sometimes poke through, but overall, fabric is effective at weed control. Better weed control can be achieved by adding more mulch on top of the fabric. Many gardeners add decorative wood or stone mulch on top of fabric to enhance its appearance. Landscape fabric works best for shrubs and nonspreading plants.

 

Pine Bark: Pine bark is usually dark in color and lends an attractive, woodsy look to your garden areas. Various particle sizes are available, from shredded bits to chips and nuggets. The only downside to pine is that it can float and therefore dislodge after heavy rain so it works best on nonsloping areas. Also, pine mulch may sometimes harbor insects, such as termites.

 

Pine Needles: Pine needles are attractive, especially for wooded lots. This type of natural mulch works well for acid-loving shrubs, trees and plants, such as azaleas, camellias and rhododendron, and allows water to flow through easily. Pine needles can be hard to find, though, and may not be available in all parts of the United States.

 

Rubber Mulch: Rubber mulch eliminates the need for annual mulching. This type of mulch is usually offered in natural-looking colors, such as redwood. Rubber mulch is very effective at weed control and is heavier than wood mulch so it won't float away. Rubber mulch is often used in playgrounds because it is softer than some of the natural materials and has more give.

 

Shredded Hardwood Mulch: Shredded hardwood mulch works well at keeping down weed growth and does not wash away easily. Shredded hardwood lasts longer than other wood mulch and is very attractive.