Mulch helps plants and keeps soil healthy. All plants greatly benefit from mulching.
The application or re-application of mulch is important to provide your garden once per year. Cedar or cypress bark is recommended due to its resistance to rot and fade, and has the ability to stabilize soil in beds and retain moisture. Cedar also repels insects. Other grades of mulch are available, but you will find that they will fade and float away, thus not being as effective.
Here are some of the benefits:
- Conserving soil moisture
- Preventing crusty soil at the surface
- Maintaining the ideal soil temperature
- Reducing weed seed germination
- Reducing weed growth
- Preventing the splashing of soil fungus during rain and watering
- Lessening cold damage
- Slowing soil erosion
- Reducing soil compaction
- Adding a clean and beautiful look to a landscape
Following the LSU AgCenter's recommendation, we suggest mulching annual bedding plants and herbaceous perennials to about 1'' deep; shrubs to 2'' and trees 3-4'' deep.
Be careful not to use excessive amounts of mulch. If it is too deep around plants it creates health-related problems for plants. Research has shown that mulching deeper than 4'' is not healthy.
You can add new mulch to old mulch and do not have to use the same mulch material each time.
Installing mulch in the fall is beneficial because it protects plant roots from extreme temperatures in the winter months and also helps to preserve moisture in these dryer months.
Keep mulch away from the base of a tree, creating a donut-hole affect. The mulched area should extend to the drip line of the tree branches, or at least cover a 4-5 foot diameter area around the trunk. Avoid volcano mulching, which is created when mulch is piled up around the trunk. When mulch is placed right next to the tree base, you can see the ill effects on the trunk. Too much moisture will gather around the base, and the bark can decay. When decay occurs, serious disease organisms may more readily enter the plant. Mulch is better when applied heaviest around the edges of a tree’s roots.
Mulching can be a big task in the fall, if you have multiple garden beds. Organic mulch should be composted or otherwise treated before use. The step kills insects, weed seeds and disease microorganisms. The texture of composted mulch generally is more uniform, which also means better curb appeal.
A long-lasting organic mulch option is pine needles or shredded bark, such as cypress or cedar. Composted leaf litter will work, but it may increase weeds if not thoroughly composted.
One mistake that people make is putting down less mulch to trying to stretch their dollar. Make sure to keep the standard inch layer depending on what you are needing to mulch. If the mulch is not thick enough, it won't do its job of insulating roots and reducing moisture loss.