When fall starts to set in, it’s a good time to start thinking about putting your garden to rest for the winter. One necessary chore is mulching, which helps put organic matter and nutrients back into the soil and protect perennials from harsh cold. Here are six mulches available to the organic grower, the pros and cons of each, and how to employ them.
Hay is dried grass usually sold in square bales. Good hay is one of the cheapest and best forms of fertilizer you can buy, but bad hay can be one of the most costly, killing plants and depositing unwanted weed seed. If you’re considering using hay, it’s good to know its origin and how it was grown. Many people mistakenly assume all hay is organic; however, some conventional farmers spray hay fields with chemical fertilizers or broadleaf herbicide, which can kill garden plants. Hay cut at the wrong time can also contain large quantities of weed and grass seed. If you can talk to the farmer, they’ll be able to tell you when it was cut and if it was sprayed.
- Pros: cheap fertilizer; breaks down easily
- Cons: can contain weed seed; hard to find chemical-free sources
- How to use: Shake hay onto clean soil in loose mounds past your ankles or higher. It will slowly compact over the season, but should remain thick enough to block out weeds. Reapply every four to six months.
Straw is the dry stalks of grains after the seeds have been harvested and can be easily spread onto gardens. Although not as nutritious as hay, it’s less likely to add weeds to the garden or kill garden plants, as even conventionally grown straw is not typically sprayed directly.
- Pros: easy to spread; looks tidy; typically safe from weed seed
- Cons: high in carbon/low in nutrients; hard to find organically grown.
- How to use: As with hay, shake straw onto clean soil in mounds past your ankles or higher. It will slowly compact but should remain thick enough to block out weeds. Reapply every four to six months.
3. Wood Chips
In terms of perennial trees and flower beds, it’s hard to overlook wood chips as an excellent mulching option. Wood chips take longer to breakdown, thus lasting longer than hay or straw, andmay temporarily draw nitrogen from your soil to help them decompose. It’s a good idea to add a little organic fertilizer to your garden before mulching over it with wood chips. Wood chips are typically available at your local landscaping or garden supply store, but you might even contact your local phone service provider to see what they do with their wood chips from downed branches and trees. They might be willing to bring you a load for cheap.
- Pros: long-lasting; can be inexpensive
- Cons: Temporarily draws nitrogen from soil, not great for annual gardens.
- How to Use: Spread a 1- to 2-inch layer around perennial plants, leaving a little space between plant and mulch to prevent rot issues. Reapply every six months.
Although compost can definitely make a fertile ground cover, it breaks down quickly and may feed weeds more than it discourages them. Consider adding a little around plants then placing another type of mulch on top of the compost to keep weeds from coming up.
- Pros: adds nutrients and organic matter
- Cons: encourages weeds
- How to use: As a mulch, spread thickly around plants, but consider covering with a shallow layer of hay, leaves or straw to keep weeds from thriving. Apply once per season.
5. Shredded Leaves
Leaves can be inexpensive, nutrient-rich mulch for the garden, but it’s a good idea to shred them first, which can easily be done by running over them with a mower. The bag on the mower should collect the leaves for you along with some grass clippings, which is good mulch, too. Shredded leaves break down slowly, so although they work fine in annual gardens, they work best for perennial flowerbeds and around trees.
- Pros: cheap if not free; high in nutrients
- Cons: breaks down too slowly for annual gardens
- How to Use: Spread shredded leaves in a 1- to 2-inch layer around beds. Leave a little space between plant stems and mulch to avoid rot. Apply once a season.
6. Grass Clippings
Grass clippings are very high in nitrogen and can make a great annual garden mulch––acting like hay but without the seeds. However, taking grass clippings from your lawn will remove some of the lawn’s natural fertility and can potentially hurt its overall health.
- Pros: high in nitrogen; excellent fertilizer and mulch.
- Cons: robs lawn of nutrients
- How to Use: Spread a 2-inch layer around gardens. Apply throughout growing season.
About the Author: Jesse Frost is a Kentucky farmer, blogger and author. He and his wife run a small, off-the-grid farm in southern Kentucky called Rough Draft Farmstead, where they raise vegetables and livestock naturally.