Mulching is an essential component of the garden that is often overlooked. It can save time in the long run by reducing time spent weeding, watering, fertilizing, and controlling pests. Let’s look at how to use mulch in the permaculture garden and what types of materials to use.
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Mulching: An Extra Task?
Strapped for time, many of us busy gardeners barely find time to plant and harvest, let alone keep everything weeded. When it comes to mulch, it may seem like an extra task on the to-do list, but it is an essential component of the permaculture garden. Mulch will create a healthier ecosystem and reduce the amount of time required for other maintenance tasks.
WHAT IS MULCH?
Mulch is a biodegradable layer of organic material added to the top of soil in a garden or landscaping. In the permaculture garden, mulch mimics the forest floor, which is usually covered with herbs and shrubs, sticks and twigs, and leaf litter.
In nature, bare soil equals damaged soil.
WHY MULCH?
Mulch does all of the following good things:
- Retains moisture
- Prevents erosion (See 5 Ways to Prevent Erosion)
- Creates humus
- Fertilizes
- Suppresses weeds
- Makes an attractive top dressing
Note: Your mulching practice will have a lot to do with your climate and season. Gardeners in hot/dry climates will mulch more thickly to retain more moisture and protect from the hot sun. Gardeners in cool/wet climates will use a thinner mulch that will protect the soil from washing away while allowing excess moisture to evaporate to reduce fungal issues.
In my climate, where we have cool/wet springs and hot/dry summers, I mulch lightly in the spring and thickly during other times of the year.
Mulch is a crucial element in the no-till garden.
TYPES OF MULCHES AND THEIR USES
I like to focus on using plants and free materials as mulch. I’ll review types of mulch such as living mulch, green mulch, leaf mulch, and what I call my ‘magic mulch combo’.
swiss chard border with sweet alyssum living mulch
Living Mulch
Living plants—either annual or perennial—planted underneath a primary crop will help to suppress weeds, retain moisture, reduce soil erosion, and create habitat for beneficial insects.
Use annual plants as mulch in the vegetable garden, and perennial plants as mulch under perennial crops such as fruit trees.
Many people wonder whether a living mulch will smother the primary crop. Consider the forest or prairie, where plant species naturally grow intertwined or close together. Different plants have different root structures; some are shallow and wide, while others are narrow and deep. A variety of root structures planted next to one another will not compete for nutrients.
One of my favorite living mulch + vegetable combinations is Swiss chard and sweet alyssum. I also like to plant comfrey under my fruit trees.
A Few Examples of Living Mulches
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Annual Mulches |
Perennial Mulches |
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nasturtium |
|
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sweet alyssum |
rhubarb |
| calendula | |
chopped comfrey; ready for spreading as a green mulch
Green Mulch
Green mulch is also called “chop-and-drop” mulch: Green weeds or other plants that are cultivated to protect bare soil and provide nutrients (fertilizer) to major crops.
Have you ever wondered why many of those pesky weeds have such deep taproots?
Dandelions, for example, heal bare earth by dredging up nutrients with its deep roots. We can take advantage of this free and abundant resource by mulching and fertilizing with dandelion leaves.
Learn more about weeds: when weeds are good and 5 weeds you want in your garden.
Common Green Mulches (Many are Weeds)
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Rhubarb Leaves, |
Lamb’s Quarters (5) |
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Chickweed (3) |
Parsley (4) |
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Chives (2) |
Purslane (3) |
|
Comfrey (6) |
Yarrow (4) |
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Dandelion (7) |
(#) indicates the number of nutrients the plant accumulates in its leaves
Chart information above is taken from Gaia’s Garden: A Guide to Home-Scale Permaculture, 2nd Edition
To use weeds for green mulch, cut them at the base, leaving their roots intact to feed beneficial soil organisms. Chop the green matter roughly into 2-3 inch pieces, and lay the green mulch on top of the soil beneath (but not touching) the garden crops. For a more attractive look, green mulch can be topped with a layer of leaf mulch or wood chips (see ‘Magic Mulch Combo’ below.)
Would you like to learn more about improving the biodiversity of your garden, reducing maintenance, and increasing yield?
You’ll find loads of information just like this in my book, The Suburban Micro-Farm.
broccoli seedlings mulched with chopped weeds
Leaf Mulch
Leaf mulch is an attractive top-dressing in the garden, but also helps retain moisture. We collect leaves from many of our neighbors, shred them with the lawn mower or leaf mulcher, and pile them in wire bins for use throughout the year.
Walnut leaves should not be used, as they have a chemical called juglone that suppresses healthy plant growth in all but a few plants. Oak leaves should be used only when mixed with other leaves because they break down slowly and contain tannins that can affect the soil composition.
Leaf mold (leaves that have composted for 2-3 years) is an excellent soil conditioner.
shredded leaf mulch in the garden bed
Wood Chips
Wood chips can be delivered—often for free—from local tree services (giving the driver a tip may ensure more deliveries in your future!). Wood chips are a perfect mulch to use around perennials. They should never make contact with the stems or trunks of the plants.
Wood chips that have broken down for 2-3 years are a gold mine of a soil conditioner. Use them without caution in the vegetable garden, under fruit trees as an attractive top dressing, or in the ‘Magic Mulch Combo’ in place of leaves.
*Magic Mulch Combo*
A study was done at Michigan State University in the 1990s that researched leaf mulch and whether it contributed to weed suppression or fertilization. The researchers found that leaf mulch did not serve much value as a weed suppressor or fertilizer source by itself.
When coupled with a nitrogen source (think green mulch), the weed suppression and fertilization levels went up. So I’m a proponent of composting in place just like you would in your compost bin, by layering the greens and the browns.
‘Magic Mulch Combo’ of grass clippings topped with leaf mulch.
Though I use many types of green mulch around the garden, my favorite combo is using the abundant grass clippings from my neighbor. We piled them thickly–about 1 to 2 inches–in the garden beds (but not touching the plants) and topped with an equally thick layer of shredded leaves.
The gardens are happy, I’ve kept more organic material out of the waste stream, weeds are few, and it looks appealing with the leaf mulch on top. It also solved my problem of not having enough room in the compost bins to accommodate all of the grass clippings from the neighbors.
Preparing the Garden for Winter
Another ‘Magic Mulch’ option is using composted animal manure (horse, cow, chicken, rabbit, etc.) in place of green mulch. In the fall spread a thick layer of composted manure over the beds and top with a layer of shredded leaves or composted wood chips. This will not only protect the soil from the harsh winter temps, but it will also help to improve soil quality.
Note: Ask questions about the origin of the manure. Unfortunately, manure can be laced with herbicides if the animals ate from pasture that was sprayed, or it can contain pharmaceuticals.
More mulching ideas:
All in all, mulching is an important component of lasting soil health, water conservation, and time savings for the gardener. When the soil is happy, the plants will be happy, too, and you will experience fewer pest problems. You’ll thrive as a gardener, and will regenerate your soil’s fertility over time. This is part of the process of connecting to our place as active residents.
Need more ideas for building soil in the permaculture garden?
Click here to get your 19-page Guide to Organic Soil Amendments!
READ NEXT:
- 9 Organic Amendments that Improve Soil Structure & Texture
- The Lazy Gardener’s Way to Make Fertilizer
- How to Grow Perennial Sunflowers for Mulch
What’s your favorite way to mulch?
Michael says
How does adding compost and mulch in the fall in preparation for winter square with a winter cover crop? Is the mulch sufficient soil protection? I live rainy Oregon and wonder if it would be best to somehow combine a mulch with a cover crop to prevent nutrient leaching but I can’t really imagine how I’d do it. Or is the cover crop unnecessary? Any thoughts are appreciated. Great post!
Amy says
Hi Michael. You bring up some great questions about mulching. I think a cover crop acts as a green mulch, in which case other mulches wouldn’t be necessary to use at the same time. Although, a compromise might be seeding the cover crop then covering the garden with straw, which would give the best coverage while still allowing for germination.
Cover crops take some work to turn over in the spring before planting, unless you use a tiller. Each cover crop has a specific set of nutrients it adds to the soil, like different types of mulches.
I think any mulch is much better than no mulch over the winter, but if you know what nutrient challenges your specific soil has, you might be able to choose the best mulch for the job. I don’t like to get too scientific here, so I just vary mulches each year to add variety.
I like that you’re already planning ahead for overwintering!
Star Schipp says
Thanks for the list of green mulches – I didn’t know you could use plants like nasturtium, comfrey or yarrow as mulch. I always learn so much when I visit you!
http://estleschippfarm.blogspot.com/2014/12/4-bee-products-with-health-benefits.html
Jean Obrist says
You may want to note that rabbit manure can be used directly on plantings without composting it first. Or make a rabbit manure tea by filling a container 1/3 full of manure, then filling with water. Let it brew for two or three days, then use on garden and house plants.
Amy says
Rabbit manure is a fantastic fertilizer for the garden, although it doesn’t make a very good mulch.
Peggy Case says
Rabbits are good choppers and the manure falling through the cages is ready for using in the garden. Dump your peelings and unused veggies and weeds in the rabbit pen and the rabbits work night and day to produce the manure.
Rabbits are fun to watch as well as chickens. Two cute chickens in a cute coop means two fresh eggs a day. That is a lot to use in a week, unless you have a few egg-breakfast eaters. I used to eat one scrambled egg every day mixed with sauteed chopped veggies, but now only every other day. On egg day, I have a piece of nutty/seedy 12 grain toast with avocado instead of butter. I usually top the egg/veggie scramble with marinara sauce.
On the off day, I have steel-cut oats with raisins, chopped apple, cinnamon and walnuts, topped with skim milk.
Both of these breakfasts include a smoothie of banana, skim milk, sour cherries, flax seed, ginger and cinnamon.
Kathy says
How can you use purslane as a green mulch without ending up with an unwanted cover crop of it? I pull as much as I can manage and feed it to the chickens. It’s a miserable, invasive pest.
Amy says
I think purslane is an excellent living mulch. Just pull it up if it’s touching the stems of your crops, otherwise, I would let it go. It’s high in vitamin C and makes an excellent edible green. It is fertilizing the soil with potassium and other trace elements. There’s a good discussion about purslane in the comment section of my post 5 Weeds You Want In Your Garden. Happy gardening 🙂
Diane Keane says
Hi Amy, I’m new to your excellent site and exploring older posts. I have a question with regard to using other plants as living mulch. Don’t they compete with the primary plants for soil nutrients and water, just like weeds would do? Thank you.
Amy says
Good question. When using a living mulch, it will need some maintenance to make sure it is acting as a benefit. For example, I plant living mulches between rows of crops, and I periodically (about once a month) cut it back so it isn’t infringing on the crop roots and is still allowing for sun and air circulation.
Another thing you can do is study the root structure of the crop as well as the root structure of the living mulch. If their root structures are similar, they will compete more readily than two different root structures. For example, a deep taproot–like dandelion–wouldn’t compete with shallow, fibrous root structure, as they receive their nutrients and water from different levels of the soil. An example of this is my swiss chard/sweet alyssum combo.
Kristine Brooks says
Hi Amy,
I am really enjoying your blog and the knowledge you share. I have a question about partially decomposed wood in the soil.
I bought a small property in New Hampshire, where the home used to be heated with a wood fired boiler. Sometime in the past 15 years or so, that system was replaced, but the pile of wood was not removed when the boiler was, so I have an area roughly 30’x30′ that has had wood rotting and decomposing in it for a very long time. I have been cleaning out the pieces of wood that are still together enough to move, but there is a lot of detritus from the length of time it has been sitting. I have been thinking that this is probably a really great place to plant my kitchen garden, but haven’t found much information about whether I need to amend the soil in any special way because of all of the wood. I am very interested in the no-till garden and wonder if I should just contour this part of the property, as it is all on a slope, and go to town. Can you give me any advice or point me in the right direction or give me the right key words to search out an answer? Much appreciated, I know you are busy gardening. Thank you for any help you can give me.
Amy says
I would think this would be excellent soil to plant in. The Back to Eden garden style is a big proponent of gardening in decomposed wood chips. You may have to experiment with what you plant there, as perennials (asparagus, fruit trees, berry bushes) and fruiting vegetables (i.e. tomatoes, peppers) may do better than your regular annual vegetables like leafy greens and root vegetables. But this is just a guess, and it’s probably the best free soil you could find. Good luck!
Jen says
How or what do you use to chop your comfrey or other large leafed cover crops into 2-3″ pieces for mulching? I have quite a bit of rhubarb I could use, but it’s so time consuming just cutting it in peices small enough to put in the compost, that I sometimes just throw it in the garbage if I’m short on time. Do you have a quick method, or is it going to always be time consuming?
Amy says
Chopping comfrey: We put the leaves in a 5-gallon bucket and shred them with hedge shears. Takes just a couple of minutes to do a bucketful. If I have just a handful of leaves then I’ll use my hand pruners. If you’re mulching under perennials, chopping isn’t entirely necessary, as the leaves will break down pretty quickly especially if tucked under existing mulch.
Also, no need to throw organic matter in the garbage! If you have whole leaves that you won’t be using for mulch, toss them into the compost bin. Creating a permaculture homestead is about closing the loop in the waste stream and taking advantage of the nutrients that your site creates for you for free. 🙂
John Scarborough says
Here in North Florida I use a similar plant for chop-n-drop mulch.
Yellow Mexican sunflower, Tithonia diversifolia, and its red/orange relative, Tithonia Rotundifolia.
They die back to the roots in a cold winter here but quickly grow out from the roots in the spring and can get to 30 feet tall. They can be cut back for green mulch several times during the summer. I have heard the mulch can match chicken manure compost for nutrition.
Michael says
Is there any reason not to plant comfrey as a living mulch in a large area around fruit trees as opposed to clover or something similar? I have a small orchard 40 feet by 75 feet and would like to avoid mulching and weeding all the time. Thanks.
Amy says
I always encourage planting comfrey under fruit trees or in a food forest area for building nutrient-rich soil. It will prevent weeds underneath its giant leaves, but overall, it’s not meant to be a ground cover. You’ll still have spaces between the plants that would be open to catching weed seeds.
A multi-species cover crop will be great for keeping weeds out as well as attracting beneficial insects. It’s also low maintenance because you can mow it once or twice a year to maintain and provide natural mulch.
Underneath the trees you could sow seeds like clover, yarrow, and dill along with the comfrey, and in the walkways you could seed ryegrass. This will add nutrients, bring in a lot of beneficial insects to help with pest control, as well as pollinators.