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A fresh pile of free wood chips sits next to the remains of an aged pile. Time to get mulching!
It doesn't get cheaper than free. Here are 3 ideas for using wood chips around your property.
We gardeners and homeowners love to find free and useful materials to improve our home landscapes. Let's face it: keeping up your gardens and grounds can get pretty expensive very quickly. I have discovered that free wood chips are easy and handy for a number of purposes. Before long, you too can enjoy the benefits of this free material.
Wood chips make a wonderful mulch for weed suppression and moisture retention. This means they will save you time (less weeding and watering), money (free mulch, and less spent on chemical controls), and water (a precious resource to be conserved whenever possible). Once they have broken down into compost, wood chips become the very definition of humus, that rich and crumbly material that enriches forest soil. Thus, they provide valuable soil nutrients and physical benefits to encourage plant growth in garden beds. What's not to love?
Where to get wood chips
The first step is to find a source. It might take a bit of calling around and some patience, but you probably have a number of options:
Your local utility. Call your local electric company to see if they produce chips when clearing around power lines. Or (and this might be a better bet for quick delivery), if you see a crew at work on the side of the road, stop and ask the workers if they would be willing to drop off a load of wood chips for you.Local arborists or tree services. Look up a few arborists in your area and ask to be put on their list for wood chip drop off. Your municipality or local solid waste facility. Some municipalities will deliver free wood chips (and/or free leaf mulch), or you might be able to pick up a load at the solid waste facility if you have a truck or trailer.Your neighbors. If you happen to have neighbors doing tree work, ask them if you can take the byproducts of the job.
Be sure to either specify very clearly where the chips should be dumped, or be present when you receive your delivery. No one wants to come home to a driveway blocked by a large pile, or have a nicely maintained lawn area burned out by chips dumped in the wrong spot.
But I've seen dire warnings about the hazards of using wood chips!
There is a lot of conflicting information out there about whether you must age wood chips before using them, and whether they are truly beneficial. The most often-cited concerns revolve around disease potential, nutrient tie-up, and soil acidification.
Some folks have expressed concern that wood chips containing diseased tree material could transfer pathogens to plants where wood chip mulch is applied. It's true that when you get a load of free wood chips, the exact contents and nature of the ingredients are unknown. It's possible or even likely that some of the trees that were chipped up were diseased. However, diseases that afflict growing trees generally do not persist once the tree has been killed and chipped, because the decay organisms kill the pathogens.
Another common warning about using wood chips, especially fresh ones, is that they will suck the nitrogen from the soil around your plants and starve them. It is true that wood chips are very high in carbon, and low in nitrogen. As the wood chips break down, the decay organisms that work on them require nitrogen to "eat" the chips. The organisms do take nitrogen from the immediate vicinity (soil surface). However, there is no evidence that nitrogen deficiency occurs deeper in the root zone. If you are concerned about a nitrogen deficiency, you have three options: 1) age your wood chips for several months before using them as mulch; 2) place a layer of compost down on the soil surface around your plants before applying wood chips; or 3) refrain from using wood chips around shallow-rooted annual plants or vegetable crops, favoring instead areas with established perennials, shrubs, or trees which have deeper root systems.
A third concern relates to allelopathic compounds in wood chips suppressing plant growth. Many trees, such as black walnuts, produce chemicals such as juglone, which naturally prevents vegetative competition around the tree. Some people have expressed the worry that these suppressive compounds, if present in wood chip mulch, would likewise discourage plant growth. In fact, allelopathic chemicals have not been shown to affect established plants; rather, they act to prevent germination of new seeds. So, if anything, this would be a mark in the plus column, because wood chip mulch naturally suppresses weed seed germination. Of course, you wouldn't use wood chips on a new vegetable seedbed, because the texture is too coarse for baby plant seedlings anyway.
Finally, some sources warn that wood chips can acidify your soil, reducing the pH to a level below the optimum for plant growth. In truth, most soils, unless they are extremely sandy, are able to resist sudden changes in pH due to natural buffering capacity. It's actually pretty difficult to change a soil's pH without using chemicals or significantly changing the soil content throughout the root zone. Adding a layer of wood chips on the soil surface does little to modify the acidity of the soil below.
Linda Chalker-Scott at Washington State University has written extensively on the use of wood chips, based upon evidence from academic studies. Check out one of her concise publications here.
Use #1: Wood Chip Mulch
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Use wood chips as a mulch in perennial garden beds.
Wood chips used as mulch have multiple benefits. A mixture comprising wood, bark, twigs, and leaves, wood chip mulch contains pieces of different sizes and characteristics. It is porous and light, but a 4-6 inch layer added to perennial beds or around growing trees effectively prevents sunlight from reaching the soil surface and keeps weeds from sprouting. Wood chip mulch absorbs moisture from rainfall and lets it gradually percolate into the soil below, instead of running off. Once the moisture is there, the mulch also helps keep the soil moist by preventing evaporation. Finally, wood chips are a natural material that will gradually break down to become rich, organic compost, which adds valuable nutrients and tilth to your garden bed.
Wood chip mulch is generally recommended more for perennial beds and around trees, and less as a suitable mulch for vegetable or annual flower beds. Since it is coarse, it might not be the best choice for vegetables and annuals; but it is worth it to experiment and see whether it works for you. I have found that aged wood chip mulch seems to work excellently well even for vegetable beds (though not as a fine seedbed, as discussed above).
Use #2: Weed Suppression and Trail Surfacing
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Free wood chips make the perfect mulch to suppress weeds around garden beds.
Wood chips are perfect for walkways between garden beds or for lining trails around your property. They are soft and springy, natural, renewable, and easily replaced. A joy to walk upon.
The photo above was taken a couple of years ago in my vegetable garden, which I created entirely from free materials (except for the crop plants).
To establish the garden, I followed a modified "lasagna gardening" method, laying down cardboard directly on the existing grass and weeds. Then I created beds of rotted horse manure to form what I call "candy bar" raised beds. The candy bars sit on top of the soil, but don't have defined sides like many raised beds. As the cardboard and manure break down, the roots gradually gain access to the deeper soil underneath, but in the meantime, there are zero weeds. By the time the cardboard disappeared, there was a nice, undisturbed layer of compost to keep dormant weed seeds from germinating. In between the beds went a healthy layer (at least 6 inches) of wood chips directly on top of the ground (no cardboard). This was sufficient to suppress most weeds. The weeds that did sprout were easy to pull from between the large wood chip pieces.
A major advantage to the lasagna/candy bar raised bed surrounded by wood chip mulch leads me to the third use for wood chips:
Use #3: Wood chip compost as a soil amendment
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1. Pull away the top layer of wood chips that are still recognizably chips.
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2. Work your way around the bed, scraping the layer of decomposed wood chips (compost) up and over onto your garden bed.
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3. The good stuff.
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4. Reshape the garden bed and pull the top layer of chips back over the bare ground.
After a couple of growing seasons, as you keep adding layers of wood chips around your garden beds, a delicious layer of humus will form. This becomes excellent organic matter that you can easily add back into your garden beds. If you use the candy bar raised bed method, all you need is a garden hoe. First, pull aside the top layer of recognizable chips. Underneath you will come to dark, moist, crumbly compost. Next, use a hoe to scrape this layer of organic material up and onto your garden bed. You will probably be able to tell exactly where this ends and the existing soil starts below it. It's okay if you scrape up a bit of the native soil. Work your way around until it is all piled up. Then simply reshape your bed and pull the wood chips back over the bare ground. Now you are ready to add your next layer of chips and start a new growing season in your refreshed planting bed.
You can also pull aside the top layer of chips and scrape the compost up into piles, then transport via bucket, barrow, or wagon to other areas where you'd like to add organic matter. What you have here is a wood chip two-fer: free weed suppression and walking area, and then free compost. It doesn't get much better than that.
Terrapin Bonus
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A recently hatched diamondback terrapin, which emerged from a wood chip-mulched garden area.
And now, for your enjoyment, a picture of a newly hatched diamondback terrapin, which I found emerging from underneath the wood chip mulch recently. If you live on the Eastern seaboard near any brackish water source, you can encourage diamondback terrapins with wood chip gardens and other naturally planted areas (not lawn). Terrapins prefer areas that are about 20-30% vegetated and have sandy soil. They will lay eggs in the early summer and leave the nest unguarded. Babies emerge either in late fall or the following spring. Their gender is determined by temperature: warmer soil temps produce more females, while cooler temps produce more males. The babies are on their own from the time they hatch out. They have many predators both as eggs and as youngsters. If you see a female laying eggs, stay far away until she is completely finished and leaves the area (they are easily scared off). You can help to protect the babies by constructing a wire nesting cage that you stake down firmly over the nest site. Holes in the wire should be large enough for the babies to fit through (about 2-3"), but small enough so critters like raccoons, skunks, and opossums cannot enter to dig up the eggs. It's hard to beat the joy of discovering a baby terrapin newly exploring the world.
So there are three wonderful uses for free wood chips, along with some of the benefits to be derived. Have you had success with wood chips? Please add your questions, comments, and ideas below. Let me know how it goes.