Your landscape is a large living investment and like most investments the more information about it, the more you get in return. Most of us regard mulch as having one function, to give our landscape a fresh new appeal. The truth is, properly laid mulch has many other functions that are vital to the health and life of our plants.
There are basically two types of mulch, organic — such as hardwood, bark chips, leaves and pine straw that easily decompose, and inorganic — such as stones, brick chips and dyed rubber that are permanent. Although inorganic mulches have their place in the landscape, this tip sheet will be limited to the use of organic mulches.
Why Should I Mulch?
- Mulching is one of the simplest and most beneficial practices you can use in your landscape and can give your planting beds a uniform, well-cared for look.
- Help maintain soil moisture. Evaporation is reduced, and the need for watering can be minimized.
- Help control weeds. A 2- to 4-inch layer of mulch will reduce the germination and growth of weeds.
- Serve as nature’s insulating blanket. Mulch keeps soils warmer in the winter and cooler in the summer.
- Improve soil aeration, structure (aggregation of soil particles), and drainage over time.
- Improve soil fertility.
- Can inhibit certain plant diseases.
Plants growing in a natural wooded environment have their roots anchored in a rich, well aerated soil full of essential minerals. Urban landscapes, however, are typically a much harsher environment with poor soils, little organic matter, and large fluctuations in temperature and moisture. Applying a 2 – to – 4 inch layer of organic mulch can mimic a more natural environment and improve plant health.
While mulching can be beneficial to your landscape, if improperly applied it can be equally harmful. Most organic mulches must be replenished but the rate of decomposition varies. Coarser mulches may remain intact for many years while finer mulches many need replenished every year or two.
- Define the edges of your landscape beds using a garden spade or power edger. Cutting a 3 to 4 inch deep trough along the edge of your landscape bed will keep mulch from bleeding into the turf.
- Check the depth of your existing mulch. If there is an existing layer of mulch, either remove and replace with fresh mulch or till the existing layer.
- Not too much! Deep mulch can lead to excess moisture in the root zone. Remember recommended mulching depth is 2 to 4 inches.
- Piling mulch against the trunk of plants can stress stem tissues and may lead to insect and disease problems.
- For trees, the mulch bed should be as large as the drip line of the tree. This will ensure the feeder roots, located near or even beyond the drip line of the tree, will be protected from drying out as quick and receive nutrients from the mulch.
- Thick blankets of fine mulch can become matted and may prevent the penetration of water and air. In addition, a thick layer of fine mulch can become like potting soil and may support weed growth.
- For landscape beds that do not drain well, apply a thinner layer of mulch.
Remember, your landscape is a large living investment and the more information you know about it, the more you can expect in return.
by: Steve Combs