How to Mulch a Flowerbed

Many kinds of materials can be used as mulch, but shredded bark -- such as pine, cypress or cedar shredded bark -- is most commonly used. Although a freshly mulched flowerbed is visually appealing, the right type of mulch also can feed your shrubs and other flowering plants with vital nutrients as it decomposes over time. Educate yourself before heading to a garden center to ensure you load up on the most beneficial mulch for your landscaping needs.

Laid properly, mulch provides soil with adequate protection from sunlight during the hot months of summer and makes plants less susceptible to drought by keeping the soil moist for a longer period of time than normal between waterings. During winter cold snaps, mulch prevents plants from heaving -- naturally being lifted out of the ground -- because mulched ground shrinks and expands less during freezes and thaws. Mulch also protects soil from being compacted during heavy rains, which means the soil remains well-aerated, and prevents the growth of grass and weeds that can steal water and nutrients from plants.

No matter your location, it's critical to add mulch when the soil is warm and moist -- typically mid- to late spring through autumn. Laying mulch in fall helps to maintain soil temperature because mulch acts as a natural insulation. It keeps soil warmer, providing an extra layer of protection from cold temperatures and other adverse weather conditions, according to an article on the Bob Vila website. Avoid applying mulch in winter or early spring, when the ground is too cold, or in summer when the ground is dry.

Although various materials can be used for mulching, all mulch falls into one of two categories: organic and inorganic. Both types help to protect soil from compaction, extreme temperatures and weed growth while retaining moisture, but organic mulch breaks down over time and releases beneficial nutrients into the soil. With the wide variety of mulch available at garden centers and plant nurseries, choosing one kind is largely based on personal preference.

Organic mulch, such as grass clippings, leaves, tree bark, manure, leaf mold, cocoa hulls and compost, feeds the soil. The fine texture of grass clippings, chopped leaves, manure and leaf mold means they decompose quickly and require more frequent replacement than, for example, tree bark mulch, which is larger and thicker.

Cocoa hull mulch, although fragrant and considered visually appealing, is toxic to dogs. Additionally, cocoa hull mulch attracts pests if it does not have adequate time to dry out between waterings, and it develops mold when used in hot and humid climates.

Dark-colored mulches absorb sunlight and warm soil -- a benefit in cool climates but a disadvantage in hot climates.

Pebbles, plastic, recycled tire pieces, rocks and gravel are common inorganic mulches. They suppress weeds and conserve soil moisture but offer no benefit to the soil. Additionally, it's difficult to keep most inorganic mulch from spilling out of a flowerbed and onto lawn or sidewalk.

Because of the intense heat they absorb, rocks, including pebbles and gravel, work best in a specialty garden, such as a cactus garden. Because small rocks can be thrown by a lawnmower blade or weed trimmer, using small rocks in a flowerbed near grass is a safety issue.

Although more expensive upfront, plastic mulch and rubber tire mulch end up being cost-effective alternatives because the inorganic material of which they are made takes years to decay. Also, plastic mulch and rubber mulch deter insects, but that includes insects that benefit plant and flower growth. The long-term safety of rubber mulch is questionable because it may release harmful chemicals into soil, and those chemicals can get into water systems.

Newspaper, black plastic sheeting or landscape fabric

Garden hose

Scissors (optional)

Wire or plastic garden pegs (optional)

Wheelbarrow

Garden spade

Grab each weed as close to the soil as possible, and tug gently. Pull the entire weed, including its roots, from the ground to deter the plant's regrowth.

Lay a two-page layer of newspaper on top of the flowerbed's soil around, but not covering, plants. Newspaper acts as a natural, biodegradable weed barrier. Water the newspaper with water from a garden hose until the paper is thoroughly wet.

Alternatively, lay black plastic sheeting or landscape fabric instead of newspapers on top of soil. Do not use clear plastic sheeting because it will trap heat, warming the soil excessively. Cut the black plastic sheeting or landscape fabric to fit the flowerbed's dimensions and so the material will go around permanent plants. Anchor the plastic sheeting's or landscape fabric's edges with wire or plastic garden pegs. Slice an "X" in the sheeting or fabric to match where each plant exists or will be placed in the flowerbed. Lifting each X's flaps to plant shrubs or other plants. Poke small holes throughout plastic sheeting to allow water and air to reach the soil.

After putting mulch in a wheelbarrow, use a garden spade to shovel the mulch from the wheelbarrow to on top of the newspaper, plastic sheeting or landscape fabric that covers the flowerbed soil. Work in small sections of the flowerbed, moving mulch one scoop at a time and stopping frequently to spread the mulch by hand until an even layer of it is on the entire flowerbed. Don't let the mulch touch the plants.

Whether organic or inorganic, the depth of the mulch for preferred soil protection and weed prevention depends on how coarse or fine the pieces of mulch are. Lay coarse-textured mulch at a depth of 4 inches on the soil surface; coarse-textured mulch includes bark chips and nuggets. Lay fine-textured mulch at a depth of 2 inches on the soil surface. Fine-textured mulch includes pebbles, gravel, shredded leaves, grass clippings, manure, compost and leaf mold.

Do not smother plants with mulch or let mulch touch the trunk of plants, including shrubs and trees. It can kill plants by encouraging rot or diseases. Keep mulch 1 to 2 inches from plants.