Mulch – what a funny word for such a wonderful happy garden maker.
Mulching is one technique I have used for many years. I see these perfect gardens with open rich black earth and green plants beautifully profiled there, and I think, looks nice but in Permaculture one never leaves soil open like that.
For one thing, in a hot climate you are loosing loads of moisture thru evaporation since black attracts heat and that moves the moisture up and out of the soil. For another, you heat the soil which is hard on the delicate roots of plants. It will quickly kill a plant if it isn’t constantly being cooled by a drip system or often watering.
Experienced gardeners know that plants need to be moist (not wet or drenching unless they are water plants) and the roots cool. Otherwise they are being stressed and their energy goes to merely surviving. You loose production and yield.
Also raw soil often cultivated or tilled provides the perfect conditions for pioneer plants that nature provides to act as a band-aid for open top soil – we call these pioneer plants ‘weeds’. This makes for lots of labor to clear them, and lost nutrients from the soil you want to go to your plants – the ones you choose!
So, covering the raw soil is the answer. Big farms use plastic sheeting to keep down the weeds and hold in the moisture. But then they are left every season with piles of plastic which never break down or adds to the fertility of the soil, or feeds worms – our friends in the soil that manufacture beneficial micro-organisms.
Some enlightened farmers chop up and leave the last year’s stems and stalks for mulch to feed next year’s soil instead of burning them which is the old system.
But in a garden, we rarely have enough aerial (above ground) organic matter to really cover the open soil. So, the challenge is to find enough really beneficial material to act to cover and protect the soil.
During a growing season, once the seedlings are large enough to have a couple of sets of true leaves and are tall enough to withstand being surrounded by some kind of mulch without loosing sunlight, we need to properly cover the raw soil. Usually I start with a light covering around where seeds will emerge (a light sprinkling of straw which lets the sunlight reach the soil, but slightly shades). Then later, add half an inch or more of light mulch. Then once the plants are 6” or taller, they get at least an inch, preferably 2 inches of mulch.
This organic matter keeps the worms fed who come up out of the soil and munch. This leaves their tunnels lined with their poop (fertilizer) and all those lovely friendly bacteria that break down minerals in a way that roots can absorb them.
You will notice that as the season progresses, the mulch tends to thin then disappear, and once again you have raw soil. This is for two reasons. 1. The worms are eating it from underneath and 2. The organic matter is decomposing on-site. So, about mid-season it needs to be re-mulched.
So, now the question arises – what do I use to mulch.
First – what NOT to use: bags of large chipped wood from a nursery, this includes and especially not good, the kind that is dyed with red or black, or what you get delivered from your local tree service. That kind of wood chip mulch is good for pathways but not on growing beds. If it mistakenly gets mixed with the soil it tends to absorb nitrogen right out of the reach of your hungry roots. It tends to take a long time to break down.
If you want to top treat your beds with fresh manure such as chicken manure with bedding, you can do that but you must be careful to scrape it away before planting newly, and only return it to the site after you have finished patting the soil. If allowed to enter below the surface of the bed, it is too ‘hot’ (ammonia) and can kill the tender roots. A light sprinkling of raw manure is OK as long as not in great quantity.
I usually use fresh chicken manure with its bedding around hungry feeder plants like tomatoes and corn, but only after the plants are almost mature. This is a good source of ‘time released’ food for them every time it rains or is watered, but I never, spelled NEVER, dig it in. At the end of a season, when it has broken down after 4 or 5 months, then it can be cultivated into the soil, but make sure it isn’t still ‘hot’. You can tell if it is by the smell. Ammonia smells tell you it’s still way too loaded with root killing nitrogen. Just scrape it to one side if you wish to replant the area, and return it as a topper.
Don’t use hot pig or horse manure until it has decomposed for about 5 or 6 months. And never use horse manure if the horse has been ‘wormed’ by their owner as this lingers in the poop and kills your worms.
Also, a little of this raw manure goes a long way.
Exceptions to this rule about fresh manure are goat and sheep poop (or llama or alpaca) which is cool enough it can be used immediately and even dug in during planting.
A couple of good ways to feed and mulch at the same time are to use alfalfa pellets (goat food) mixed with unsprayed wheat straw or Timothy grass. Finding unsprayed wheat straw can be difficult these days because farmers are spraying their wheat even though it isn’t GMO because it desiccates (dries) wheat making it easier to harvest. So, a feed store sometimes will have bales of Timothy grass. Never use ‘hay’ which is harvested grasses and weeds loaded with weed seeds.
You can use compost you make yourself, which also feeds the soil. But I would top this off with other dry ‘brown’ material. Brown material is also a source of carbon for your plants. ‘Green’ is nitrogen rich material such as fresh leaves, kitchen waste, and fresh manure. Prevailing wisdom says the best mix is 75% ‘brown’ and 25% green to make the best soil and compost composition.
If you don’t spray your lawn, and you have a catcher on your lawn mower, every third mow or so catch the grass, and use that as mulch. Just don’t wait till it starts to seed up unless you also want to grow grass instead of vegetables.
One of the best kinds of top mulch is autumn leaves. Trees are rarely sprayed so are relatively free of chemicals. I go out when the leaves start to fall, in a local town, and look for piles of leaves by the curb which the city picks up with a big vacuum truck. I beat them to it.
I particularly look for the leaves that have been picked up by riding mowers with catcher bags because they contain not only the leaves but also grass which is a nitrogen source and they are broken down into fine particles. I stay away from piles from lawns that look perfect and have no weed plants in the yard. The perfect lawns have been sprayed! I also bypass piles loaded with acorns. I have made the mistake of using that, then for years find myself pulling baby oak trees out of my beds.
Leaves left original size if not broken up will act as a barrier on the soil, repelling water, so you have to break it up.
There is a rather inexpensive kind of chipper that just breaks up leaves but not wood or tougher stuff, can be set on top of a garbage can lined with a heavy plastic bag so the leaves go directly into that bag – saves lots of time and effort. https://www.amazon.com/Sun-Joe-SDJ616-Shredder-13-Amp/dp/B00EUU044S/ref=as_li_ss_tl?ie=UTF8&qid=1491779851&sr=8-2-spons&keywords=leaf+mulcher&psc=1&linkCode=sl1&tag=christieheavy-20&linkId=57d61e9dd48a769ee139a81e897deb5 This one is on a stand and is relatively low priced. But do some research of your own. There are better deals out there. This will make leaves into lovely mulch.
If you have pigs though, they LOVE acorns, and you could pick up bags of that kind of leaves, let the pigs eat all the acorns, rake up the remaining leaves, and put it in plastic bags over the winter for spring mulching. Their manure mixed in with the leaves would be decomposed by then and safe to use.
I ask around for farmers who grow grains which don’t spray, and ask to purchase their bales of straw. But I don’t purchase from the big semi-trailer loads of straw bales because you never know what they have been treated with. Some of the herbicides and pesticides used on grain last 5 years and will contaminate your organic soil or even kill your plants.
We have a big quality chipper we use to chip up pruned branches from our trees, dried herb gleanings after the leaves have been used for medicine, dried stems from seed saving processing, corn stalks, and various dried garden waste. We even chip rose prunings and blackberry canes. This all goes into the chipper about two or three times a year. We have a chipping party and clean up all the piles of saved organic matter. The chipper is a fine one – Troy Built – and the mulch from this is really fine and lovely.
My husband is a hobby wood worker and he saves his saw dust and fine wood shavings for me. But he is careful not to include ‘treated lumber’ which has toxic chemicals in it. Recently he has been planning a big stack of old barn wood (over 100 years old) and has been saving big bags of that. I love this kind of mulch because it’s fine enough I can use it around very small seedlings and it doesn’t bury them.
Some gardeners recommend using shredded paper from their office shredder but I don’t recommend using only paper because it tends to layer like unchipped leaves, which won’t let the water thru. (If you want to use it don’t shred plastic or treated paper, or paper with a plastic window or coating.) Mix this liberally with other organic matter like chipped leaves or from your garden organic waste chipping. This will separate the fibers allowing water in, and will break down OK.
Organic matter tends to be the hardest resource to find when building your soil or mulching your beds so when you drive around your area, keep a look out for the leaves in fall, or piles of leaves on people’s property. (I ring door bells and ask for leaf piles, and often the people are so glad to get rid of it, they say take all you want – but never just take stuff, people around here have shot guns). If you have a chipper, sometimes in the fall farms around here have corn mazes, and at the end of the season, they have piles of the stalks which you can load into a pickup.. Just be sure they haven’t sprayed them.
We make it a practice to save all the organic matter we generate from the garden, the orchard, or even kitchen waste, and we compost a lot of it, or compost in place. “Lasagna Gardening” (book) talks about layering the organic matter for soil – in Permaculture we call this practice ‘sheet mulching’. Twice a year, spring and fall, we layer our beds with saved organic matter and crushed granite, hardwood ash from the fireplace, compost, and leaves.
Of course you can purchase bags of ‘forest product’ – i.e. composted chippings from forest management and clearing – but that gets expensive. So, I’m always on the lookout for free sources. But that kind of bagged product is better used as top soil rather than mulch. It’s already decomposed.
In summary, we’re now at the end of a hot summer going into fall, so start preparing for the transition from summer to fall, which includes a last good layering of mulch to get your plants thru the hottest part of the year, which also saves on watering. When you start planning your fall garden, also start gathering in a supply of whatever mulches you can find. If you plan on winter gardening, you’ll also need abundant mulch to insulate your winter plants. This is also best served with a few inches of autumn leaves and whatever straw or dried grass clippings you can find.
When transitioning your plants from hot weather to cool weather varieties, rake off the good mulch and save it. Do your new planting into prepared beds. Sheet mulch with some crushed granite sand, some ash, and some kitchen waste, and some straw or leaves. Mix up a bucket of compost, some used coffee grounds and crushed egg shells, and a bit of worm castings if you have it. Where you put your seedlings or seeds into this sheet mulched area, dig a little hole in the sheet mulch, add a handful of the stuff in the bucket, put in the plant, then re-use your mulch around the new plant. Once all your plants are in and have matured to 5 or so inches tall, put on a generous layer of mulch which will last thru the winter.