By: Liz Baessler
Wood is a popular choice for garden mulch, and with its pleasant smell and pest deterrence, using cedar for mulch is especially helpful. Keep reading to learn about cedar mulch problems and cedar mulch benefits.
With all mulch comes the danger of wind. In areas with very high winds, it may be best not to apply mulch at all. If it’s only a little wind you’re battling, shredded wood mulch resists getting blown away better than chips. That said, cedar sawdust has been shown to negatively affect young plants and should be avoided.
The problem with using any woody material as a mulch is that it draws essential nitrogen from the soil as it decomposes. It shouldn’t be much of a problem as long as the mulch stays on the soil’s surface, but once it is mixed into the soil, decomposition speeds up and is spread evenly through the soil.
Because of this, cedar mulch problems arise in beds that are tilled regularly, such as vegetable gardens. While using cedar for mulch won’t immediately damage your vegetables, it’s a good idea to restrict it to plants that won’t be tilled every year. This does include some vegetables, like rhubarb and asparagus, which are perennials.
Cedar mulch in gardens that contain perennials should be applied to a depth of 2-3 inches (5-7.6 cm.) for vegetables and flowers, and 3-4 inches (7.5-10 cm.) for trees. If you’re laying it down around trees, keep it 6 inches (15 cm.) away from the trunk. While piling mulch up in hills around trees is popular, it’s actually very harmful and can discourage the natural widening of the trunk, making it more likely to be blown down by the wind.
For very compacted or clay-heavy soil, apply 3-4 inches (7.5-10 cm.) to help retain moisture.
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Organic mulches break down into the soil, adding nutrients in the process. They include chopped leaves, manure, straw, hardwood, grass clippings, newspaper, cocoa bean hulls, and compost, and are the best option for mulching vegetable gardens or mixed borders containing a combination of trees, shrubs, and perennials. Conversely, plastic, gravel, and shredded rubber tires are all inorganic mulches that remain in place until you move them. Certain vegetables like tomatoes and peppers benefit from the soil-warming ability of plastic mulch.
The introduction of rubber mulch to the market has changed the way many people do landscaping and gardening. In the process it has created some polarization between those who think it is a good idea and those who don’t. People who are skeptical about its effects give reasons ranging from lack of organic “aesthetics” (look and feel), to fears about poisoning their plants with unseen chemicals. On the other hand, those who think that rubber mulch has specific benefits for gardening also offer good reasons (chief among them being the reduction of carbon footprint).
Let’s take a closer look at both the benefits and disadvantages of using rubber mulch for your plants.
It provides good insulation from heat. Rubber mulch does a better job of insulating plants from heat compared to wood chips and other organic materials. In “indoor” gardens like sun-rooms and solariums, it is especially beneficial because it does not break down and emit a rotting smell.
It won’t attract insects. Unlike soil and wood, rubber isn’t attractive for insects to build nests in or gnaw on. This is particularly true for ants and termites. Some even use rubber mulch as a sort of insulation around their homes to keep insects at bay.
It discourages weed and fungal growth. Because rubber does not absorb water, rubber mulch can actually help prevent fungal growth in plants. The shredded rubber tire “nuggets” are non-porous so water and fertilizer passes through it down to the soil it rests on. Weeds cannot thrive on the rubber and can’t get through the mulch layer down to the soil.
It lasts forever. Well maybe not forever, but since rubber is very slow deteriorate, you can expect to enjoy the landscaping material for many many years without the cost and hassle of topping it up annually.
It stays in Place. Since rubber mulch is heavier than organic mulches (and water) it doesn’t displace easy and won’t float off during heavy rainfall.
It provides more design options. Available in many earth tone and designer colors, rubber mulch offers more options to compliment existing landscape elements. Unlike colored wood mulch, rubber mulch tends to hold its color for up to ten years.
It is a low maintenance option. When compared to organic mulches, the density and durability of rubber mulch translates into less maintenance and replenishment costs saving both time and money.
It provides twice the coverage. While Rubber mulch is initially more expensive it requires only a 1.5 inch depth to effectively control weed growth compared to 3 inches of organic material.
It’s an environmentally friendly option. Rubber landscaping mulch is made from recycled tires. Using this material not only helps to prevent landfilling but also also requires no tree sacrifices.
It does not decompose. Rubber mulch is not organic, so it does not decompose and will not provide the soil with organic material.
It contains chemical residues which can be harmful to plants. Contrary to popular belief both wood mulch and rubber mulch can contain chemicals. Some wood mulches are made with industrial pallets that may have come in contact with various chemicals. Rubber of course utilizes chemicals in the manufacturing process. Studies differ as do mulches themselves. The most common chemical in rubber mulch that is found to potentially affect soil is zinc. Zinc is found naturally in soil and too much or too little can affect soil quality. Some areas of the US have sufficient or even high levels of zinc in the native soil whereas other areas have a zinc deficiency. If you are uncertain you may wish to test your soil for zinc levels before making a decision on what product is the best fit for your landscaping project.
It doesn’t look and feel organic. Despite the many natural colors available some prefer the natural look and feel like real soil, wood, or stone.
The important thing is to do research prior to purchasing. Weighing the pros and cons carefully is key to deciding what’s best for your particular landscaping and garden projects.
Cedar bark, as well as providing the general benefits that many wood-based mulches provide, offers some special qualities that make it a perfect fit for a vegetable garden if applied correctly.It lasts many times longer than other organic mulches like straw and dried leaves. It adds nutrients and nitrogen to the soil as it decomposes over time, helping to increase the percentage of organic matter in the soil. Mulches also prevent the germination of weed seeds, keep the soil temperature higher, and help prevent water evaporation from the soil surface.
Cedar mulch benefits are also known to include a chemical compound called thujaplicin, which is a bacteria and fungus inhibitor. Some varieties of cedar omit chemicals that can repel moths, beetles, ants, and cockroaches.
It has been reported by some quarters that cedar can be toxic to other plants, but this is considered a myth by experienced horticulturalists.
Application of cedar mulch is very straightforward. Here are some tips:
The aroma of cedar is quite strong, but pleasant, and it’s great to think that insects and bugs will be repelled.
To maintain your mulch, keep an eye on it and make sure it has not fallen or been blown around the stems of the plants. Remove any weeds that do pop up, but non-germinated weed seeds should be held in check.
This video explains how to use cedar mulch on your veggie garden:
Although slightly different in size, there isn’t a lot of difference between cedar mulch and cedar chips. The potential cedar mulch problems that I mentioned above are only thought to occur when using cedar sawdust as a mulch. Chips or mulch, you’re fine with either.
Cedar mulch for vegetable gardens is a long life product, one that looks incredibly attractive, and has many other qualities to make it the perfect garden mulch. Definitely a good product for the homesteader looking to create a self sustaining garden.
Hi: I'm Steve and I'm a homesteader and self-sufficiency freak. I love pretty much anything that makes me less reliant on others, and more reliant on my own abilities. I try to avoid consumerism as much as possible, eat well, and try not to leave too much of a footprint during my time on this earth.
Join me for fun and adventures in homesteading land.
Benefits: Very inexpensive because it is a waste product.
Drawbacks: Very acidic and messy
Bottomline: Use sawdust only around your acid-loving perennials, like blueberries.
Acadia Tucker is a regenerative farmer, climate activist, and author of Growing Perennial Foods: A field guide to raising resilient herbs, fruits & vegetables and Growing Good Food: A Citizen’s Guide to Backyard Carbon Farming. She currently lives in Maine and New Hampshire with her farm dog, Nimbus. When she isn't raising perennials in her own backyard, she grows hops to support locally sourced craft beer in New England.