What’s the proper way to mulch?
Special to the Whig
Mulching appears to be an area of confusion for many people. As a professional horticulturist, I can find many more examples of how not to mulch than examples of a well- mulched tree or garden. Let’s first discuss the reasons why mulching is beneficial for the plants and environment and then how to mulch as well as what types are best to use.
Why mulch? Mulch is applied for several reasons, some of which are for the benefit of the plant, according to the Internal Society of Arboriculture (ISA). When the area surrounding the base of a plant is covered with mulch so there’s no bare soil, it helps the plant retain available moisture and better survive dry spells. Mulch will also protect the root system underground by insulating the soils from extreme summer and winter temperature shifts and protects the soil from erosion and storm water run-off.
Mulching can also improve the organic content of the soils and, since mulched soils germinate less weeds, that means less yard work for you. Mulching will give a protective edge from “mower blight” a harmful effect from the lawnmower man, and weed wackers. Abrasions and cuts to the trunk can be harmful and deadly to trees, allowing disease and insects to enter the wounds. When done properly, mulch helps plants retain available moisture and better survive dry spells.
Finally, top-dressed plants and gardens have great curb appeal, like icing on the cake.
How do you mulch? Mulch applications are beneficial when properly applied. Here are some “ground rules” to follow:
1. Clean a ring around the tree to an area equal to the outside drip edge of the plants. As the tree expands in girth and spreads its limbs, so will your mulched area.
2. Proper garden planning includes planning enough layers of plants to fill in under trees. The spacing at planting time should also take into account the size of plants at maturity. You will use the largest quantity of mulch the first year but less in subsequent years as the plants fill in and likely
touch each other. This is the ideal situation as weeds will not grow, soil will be well held by interconnecting root systems and you will find little open space that requires mulch.
3. Early spring, as the perennial and herbaceous break ground, is a good time to reassess your garden for mulch needs. It is easier at this time to apply mulch if needed without breaking off tender new foliage.
4. Always apply a two to four inch dressing of mulch to an area.
5. Do not cover the root collar of a plant. If you are not familiar with plant physiology, you can google plant parts on the internet to identify the root collar. You will learn to see this obviously different tissue ring at base of your plants and
make sure to not bury it under mulch.
6. Avoid the tree volcanoes that you frequently see around town. These are not mulched properly and this will contribute to the death of the plant over time as a buried root collar allows for excess moisture to build up, insects and disease to access the trunk and you to waste your valuable landscape investment.
7. When re-top dressing with mulch in subsequent years, if the mulch has not deteriorated, remove old mulch and recycle to another garden area before adding more so that you remain at the proper level of two to four inches.
What are the best mulching medias? Now that you know the why and how, let’s discuss what mulching mediums to use. There are many mulching mediums available at retail garden centers or you can choose to recycle yard waste such as dried grass clippings, pine needles, shredded leaves or aged wood chips. The choice is yours as to whether you purchase mulch or get creative.
There are several good reasons not to use shredded tire chunks or stone for mulch. Both of these choices add heat to the plant material, increasing soil temperature beyond the limit of the plants’ tolerance. These two medias will never biodegrade or add organic content to your soil, which is an important benefit of organic mulches. I feel some of the best options to use would be: • Recycling materials from your yard, properly aged • Purchasing a hardwood shredded mulch without dye. The dyes delay the natural degrading of the mulch, which hinders the addition of organic content that is so important to healthy soil. • Buying mulch with Preen, an additive that decreases the chance of weed seeds from germination, meaning you’ll have less weeding to do. Each week, a Cecil County Master Gardener will write in to share their gardening experiences or answer a gardening question. To submit questions to the Master Gardener, send them to cecilmastergardener@ gmail.com.
Some of the best mulch mediums can be bought at retail garden centers or you can choose to recycle yard waste.