Mulch Harrisburg PA is a material applied to the soil’s surface to protect, insulate, and improve soil health. Organic mulches add organic matter and improve a soil’s moisture and nutrient-holding capacity, structure, and drainage.
Shredded or composted leaves can be used for vegetable gardens, annual flower beds, and perennial plantings. They may decompose quickly and require regular replenishment.
Mulching can help prevent weeds and improve soil. It conserves and extends available water, protects the soil from erosion, moderates temperature extremes, reduces competition by suppressing weeds and adds organic matter as it decomposes. It also helps identify or mark gardening beds to limit damage by landscape maintenance equipment. Choosing the proper mulch and applying it at the right time is essential.
Organic mulches — leaves, grass clippings, straw and wood chips — degrade and enrich the soil as they break down. They also provide a more natural look in garden and landscape areas. However, they don’t prevent all weeds and must be removed manually or with a herbicide. The best time to apply organic mulch is immediately after planting or when weeds first appear, before they have the opportunity to go to seed.
Inorganic or synthetic mulches — plastic sheeting, woven or non-woven landscape fabric — are good choices in situations where they can be installed before the plants begin growing. These materials smother weeds and can be used in place of traditional or organic mulches, but they must be replaced regularly.
While the initial cost may be higher for these types of mulches, they offer long-term savings by eliminating labor and chemical costs associated with weed control. They are also better suited for xeriscaping projects and arid climates.
Before laying down mulch, it is helpful to understand what type of weeds you are dealing with in your garden or landscape. Perennial weeds with deep roots, such as field bindweed and nutsedge, can penetrate thick layers of mulch. Annual weeds such as common groundsel, prickly lettuce, and sowthistle may germinate on top of the mulch or in the spaces between the plant roots and the soil surface.
If these weeds are allowed to grow, they will compete with your plants for water and nutrients. They can also choke out the growth of desirable vegetation. To eliminate this problem, a pre-emergent herbicide can be applied to the soil surface before the mulch is put down. This prevents the weed seeds from sprouting and is most effective when it is applied according to the label instructions, ideally just before mulching.
Soil Preparation
Mulch can be made from a wide variety of organic or inorganic materials, including wood chips, bark, shredded branches, straw, compost, cardboard and even seaweed. For the best results, weeds should be removed from the area before mulch is applied. It’s also a good idea to loosen the soil with a garden fork or rake and amend it, if necessary, with compost or other soil amendments. Mulch is most effective when it is not too thick. A layer that is too deep can suffocate the roots of plants and prevent them from getting the nutrients they need.
There is some concern that certain types of organic mulches, such as bark and wood chips, deplete nitrogen from the soil because they break down very quickly. However, research by the US Department of Agriculture and Texas A&M has shown that this is not true. In fact, as these types of mulches decompose, they improve the condition of the soil by aerating it and adding nutrients.
In addition to improving soil fertility, mulch helps conserve moisture by reducing evaporation from the surface of the soil. This can save time and money spent watering as well as reduce the need for chemical fertilizers.
Mulch also helps regulate soil temperature, keeping it cooler in summer and warmer in winter, which can protect delicate young seedlings from extreme temperature fluctuations. Lastly, it helps prevent erosion by breaking up the impact of raindrops against the soil surface. It’s important to choose the right type of mulch for your soil and climate, though, as some kinds work better than others in specific conditions. For example, straw and hay mulches are great for vegetable gardens as they help to insulate the soil and can be easily spread. They are also a good choice for perennial edible crops like berries and fruit trees, as they can be dug in and used again next year. For more permanent applications, a porous landscape fabric may be a better option. This will provide an extra barrier against weeds and still allow the soil underneath to receive the most sun and water possible.
Water Infiltration
Mulch provides a barrier between soil and wind, which slows down erosion and conserves moisture. This reduces surface evaporation of rain and irrigation water, thus maximizing soil water availability for plant use. Mulch also moderates soil temperature, preventing it from becoming too hot or cold for optimal plant growth.
Water infiltration is the process of water penetrating the soil, and it can be regulated by the soil surface conditions, such as the presence or absence of mulch, soil particle size and porosity, and texture. Previous studies demonstrated that the addition of organic mulch improved water infiltration into the soil26,27.
In this study, the effects of the mulch type and thickness on infiltration were investigated by measuring cumulative and stable infiltration rates and water loss from the surface of the soil. The results showed that cumulative infiltration and the initial infiltration rate increased with the increasing mulch layer thickness, while the stable infiltration rate decreased. The results also revealed that the mulch particle size affected the infiltration characteristics.
A two-way ANOVA analysis indicated that the mulch thickness and the interaction between the mulch thickness and particle size (T x P) significantly influenced all water infiltration parameters, including the initial infiltration rate and the average and cumulative infiltration rate. However, the effect of the mulch thickness on the infiltration characteristics was greater than that of the particle size.
Organic mulches are beneficial in the weed control and soil moisture retention, but they require careful management for the proper benefit. In addition, as the organic material breaks down, nitrogen from the organic matter can become unavailable to plants. For this reason, a nitrogen test should be conducted regularly to determine the amount of fertilizer needed to avoid deficiency. Straw is a popular choice for summer mulches in vegetable gardens and strawberry plantings because of its low cost, but it can create a crusty surface that interferes with aeration. In addition, straw contains grain seeds that can germinate and harbor rodents, and it is easily blown by the wind. In contrast, wood chips and sawdust are more versatile organic materials that have a high infiltration capacity and are not prone to wind erosion.
Plant Health
Mulch helps suppress weeds and conserve soil moisture while providing a habitat for beneficial insects. It also protects plants from diseases caused by pathogens living in the soil. Some diseases infect a plant through its roots, but most must make contact with the foliage of that plant to infect it. Splashing water from irrigation or beating action of rain drops can carry disease spores up from the soil to the lower leaves and shoots of a plant. Mulch prevents these spores from getting to the plants, thus protecting them from disease (Turchetti et al. 2003).
Organic mulch materials such as garden compost, wood chippings, well rotted manure and spent hops are the best choices for healthy soil and plants. Some wood mulches, such as cypress, may have been treated with a preservative containing the chemical methyl bromide, which can leach into the soil and harm plants, especially edibles. To avoid methyl bromide, buy a wood mulch from a landscaper or arborist that chips trees and branches from local sources.
Inorganic mulches do not add nutrients to the soil, and some can even prevent nutrient uptake from the ground. In addition, some inorganic mulches can prevent aeration of the soil, which makes it hard for water and nutrients to reach the roots of plants.
Organic mulches improve soil health as they decompose and release nutrients into the soil. They also help to keep the soil cool in hot weather, which reduces stress on young plants and helps them access the available nutrients and water (Kader et al. 2019). A good layer of mulch can help the soil retain its water by reducing evaporation and thereby cut down on the frequency of irrigations. However, too much mulch can cause the soil to become compacted, preventing water and nutrients from reaching the plant roots. For this reason, it is important to aerate and amend the soil underneath a mulch layer yearly. This is particularly important when applying mulch around young plants. The most effective way to apply mulch is in small areas at a time, spreading it out as you go.