Before you break the bank buying pallets of pre-packaged and chemically altered mulch from the local home improvement or garden center this spring, take a look at another alternative for your garden--the living mulch.

A living mulch is a low-growing ground cover crop planted before or with a main crop then maintained as a living cover crop throughout the growing season. It is usually grown in between rows or around plantings. The use of a living mulch is a form of companion planting that benefits both the mulch and the main crop in various ways.

A few examples of plants that can be used as a living mulch are:

• Clovers
• Hairy Vetch
• Alfalfa
• Rye Grass

Unlike bark, pine straw or hay, a living mulch improves soil structure above and below the ground. The mulch also feeds nutrients, like nitrogen into the soil. The stem, leaf and root residues left from high-content nitrogen ground covers reduce the need for added nitrogen fertilizer. The root system of a living mulch opens the soil and feeds it with nutrients throughout the season.

Other benefits of a living mulch are:  

• Contributes nutrients to the main crop
• Erosion control
• Reduces surface water pollution
• Helps retain soil moisture
• Controls weeds
• Helps reduce disease in main crops
• Helps control insect pests
• Provides Shade

Contributes Nutrients to the Main Crop
When living mulch crops are turned over in the soil, they contribute key nutrients (nitrogen, phosphorous and potassium, among others)
to the main crop, resulting in less need for chemical fertilizers.

Erosion Control
A living mulch reduces water runoff and soil erosion around the main crop leading to much better soil productivity.

Reduces Surface Water Pollution
The reduction of surface water runoff with the continuous presence of a living mulch keeps nutrients intact and eliminates off-site movement of pesticides, ultimately protecting waterways from pollution.

Helps Retain Soil Moisture
Over time, living mulches add organic matter to the soil which helps to conserve water. The organic matter soaks up water and slowly releases it. When not actively growing, living mulches conserve and recycle soil water and nutrients.

Controls Weeds
A living mulch suppresses the growth of invasive weeds by stealing water and nutrients the weeds need to survive. Some living mulches, like white clover, provide weed control comparable to some commercial herbicide programs.

Helps Reduce Disease in Main Crops
When used in companion planting, living mulches can help suppress or eliminate certain diseases within the main crops. The use of living mulches and crop rotation are foundational in organic farming for disease suppression.

Helps Control Insect Pests
A living mulch ground cover provides a home for predators that prey on plant insects, reducing the need for insecticides.

Provides Shade
Living mulches provide shade to roots systems of larger plants keeping the roots and the soil cooler.

Although there are many benefits to a living mulch in the garden, there are also drawbacks to consider:

*Competition with the Main Crop
When first grown, a living mulch competes for water and nutrients with the main crop, reducing crop yield. However, as the mulch continues to grow, mowing it decreases water and nutrient uptake from the main crop. The mowed mulch left on the surface will decompose and add much needed nutrients and moisture back into the soil. Some mulches, on the other hand, should be lightly tilled into the soil for better soil productivity.

*Incompatibility with the Main Crop
It's important that a living mulch is compatible with the main crop. It will not only provide greater benefits, but reduce disease susceptibility. Lettuce and mustard are an example of a non-compatible companion planting.

Incorporating a living mulch into your garden is relatively easy: 

1) Before planting, make sure the garden is free of weeds.

2) Do your homework. Choose a living mulch and main crop that are compatible.    

3)Plant the main crop first. After four or five weeks, plant the living mulch. This reduces the competition between the two.

4) Take care when using living mulch seeds not to broadcast or overseed around plants. Sow seeds in dedicated areas, so they don't dominate the garden.    

5)  Monitor crops to make sure the living mulch is not dominating the main crop.      

A little research and some careful planning can help you design a garden that grows more naturally and with little chemical intervention. That's good news, not only for you and your wallet, but also for the plants and the environment.