If you ask any seasoned gardener their least favored part of gardening, you’ll likely hear the word “weeds.” In this post I shared my method of preventing weeds before they start. Part of that method – as is any sustainable non-chemical weed control – is the use of a weed barrier. In my garden, and in most backyard gardens, that weed barrier is mulch.
Mulch has many purposes. It blocks sunlight, inhibiting the growth of unwanted weeds and grasses. Mulch also helps maintain moisture levels, preventing water stress in times of drought. Natural mulch breaks down slowly into the soil, depositing valuable nutrients for future plants and creating a habitat for beneficial organisms like earthworms, bacteria, and fungi.
You do have a choice in what type of mulch you use. I am using 4 types in my garden. Each has its own benefits and drawbacks.
1. Wood Chips
Wood chips are my favorite form of mulch. This is my fourth year using them, and the benefits are many.
Benefits of Wood Chips
Free. I called my local tree service the summer before I began my first garden. When they were in my area, they were gladly willing to drop off dump-truck loads of wood chips from freshly-cut trees.
Beautiful. This is a personal preference, but I enjoy the beauty of a garden mulched with wood chips.
Easily handled. All you need is a pitchfork and a rake and you can lay down the mulch quickly and easily.
Improves soil structure. I’ve noticed over time that the parts of my garden covered with wood chips have a lighter texture, a huge benefit for my clay loam soil. In addition, the wood chips contribute to soil fertility.
Drawbacks of Wood Chips
Timing. You are usually at the mercy of when the tree service happens to be in your area. You also don’t want to put fresh wood chips on a garden; it needs a few months to “rest.”
Pest haven. I haven’t noticed this, but some sites warn that wood chips are perfect homes for pests, such as squash bugs.
You should use them fresh. Fresh wood chips tie up nitrogen in the soil, inhibiting your crops from using this vital nutrient. (Some experts say all wood chips do this and recommend you don’t use them at all, though I haven’t found it to be a problem in my garden. Regardless, wood chips need to sit for several months before adding them to your garden. Fall is recommended.
2. Pine Needles
I’ve used pine needles, also known as pine straw, off and on in my garden, simply because I have an abundance of pine trees on our property. Although they aren’t my preferred method, they do have their advantages.
Benefits of Pine Needles
Free. If you live near pine trees, this is an obvious choice. In the fall when your lawn is covered in copper, rake the needles up and put them in a pile to sit over the winter. This is great exercise, let me tell you. (That’s my optimistic way of telling you this is a lot of work.)
Excellent barrier. Pine needles matt together easily, creating an excellent barrier. They aren’t as easily handled as wood chips or straw, but once they are set down, they stay.
Slow breakdown. Pine needles won’t break down in one season like the other methods might. For this reason, I like pine needles on my walkways, which I keep constant from season to season.
Drawbacks of Pine Needles
Not easily spread. Because of their nature, they aren’t as easily spread as other methods.
Physically prohibitive: If raking pine needles is your method of acquiring them, this can be a hard task for a large garden. However, for small gardens, it is easily doable.
Note: Some resources will say that pine needles will contribute to an acid soil. Most resources, however, contend this is only true for fresh pine needles. The pine needles you’ll be putting on your garden are not fresh. I haven’t had a problem with my naturally-acidic soil, but I do incorporate pine needles into my blueberry bush beds.
Last year I ran out of wood chips and decided to try hay. I had read horror stories about how hay can deposit weed seeds in your garden but I also read an equal amount of research saying that if you lay it on thick enough the seeds can’t germinate anyway. (This was one helpful article.) So far I’ve had hay on my garden for a couple of months and it has done an excellent job keeping weeds at bay. The only places weeds and grass get through is where I did not lay it on as thick. Here are some of the advantages I’ve found so far.
Benefits of Hay
Possibly free or cheap. If you know a farmer or can get your hands on spoiled hay, you’ll likely get this source for free or cheap. Otherwise, I bought my hay from the farmer’s co-op for $7 per bale. A bale goes a long way since it is rolled up tightly. One could easily mulch 3-4 raised beds.
Nutrient-rich. I have no experience with this so far, but from what I hear, when hay breaks down into the soil it deposits a wealth of nutrients into the soil.
Excellent barrier. Matting down like pine needles, yet a little easier to work with, hay forms an excellent barrier for weeds. Although it is “puffy” when it is first applied, it quickly flattens, both to keep weeds at bay and provide a path on which the gardener to walk.
Drawbacks of Hay
Cumbersome to apply. Although not as difficult as pine needles, it can be cumbersome to apply hay to existing crops. This simply means I can’t breeze through the task like with wood chips and straw. It just takes a little extra time.
Potential chemicals. I’ve read warnings about herbicides being used on hay and straw that could destroy your garden at worst and add unwanted chemicals at best. So far I haven’t had any problems but I will keep an eye out as the season goes on.
Critter haven. Although I never found snakes in my hay, at the end of the season last year I did find a plethora of voles. At that moment I wished I had snakes to get rid of the voles. 🙂
Whereas hay is a collection of grasses harvested from a field, straw is the stalks of a wheat crop. Supposedly, straw has fewer seeds. Costing about the same amount of money, I’ve found straw covered almost the same amount of area that hay did, yet it was easier to apply. I did not find straw to be as effective of a weed barrier as the other methods, but it’s possible that I did not lay it on thickly enough.
Benefits of Straw
Easy to apply. Due to the density and length of the stalks in a bale of straw, I found it much easier to apply.
Attractive. I still prefer my wood chips, but the shiny gold nature of straw lends an appealing look to a garden, especially in comparison to the dull look of hay.
Good choice for raised beds. Because of the cumbersome nature of applying hay and pine needles, straw and wood chips are easier to apply in my 4′ by 8′ raised beds.
Drawbacks of Straw
Hard to apply on a windy day. Because straw is so light, when applied on a windy day, it might be hard to keep in place.
Less nutrient-dense. Straw is known to contribute fewer nutrients to the soil as it breaks down over time.
Potential Chemicals. Unless the straw comes from organically-farmed wheat, it’s likely chemicals have been sprayed on straw at some point in its growth. I haven’t found any clear evidence or research on the chemical load, but I could definitely see it being a possibility. This is something to keep in mind if you are trying to garden as organically as possible.
Not as effective unless applied thickly.
Which mulch will you choose?
As mentioned before, I still love my wood chips and hope to add more to my garden next year. No matter which method you choose, the key is to apply it thickly. A layer 4 to 6 inches is ideal. If you find weeds or grass growing through it, apply more.
The main takeaway from this is simply to choose a mulch. Your garden will be more attractive, your work load will decrease with less weeding, and using one of these methods will over time allow your soil’s structure and fertility to be increased in the long-term.
For a more thorough discussion about these 4 methods of mulch plus other weed control methods, you can listen to my podcast episode here:
What method interests you the most? Have you had experience with any of these?