Category — Soil

A lot of you already know the secret to good, water-conserving soil: compost.

But there may be a few of you who don’t know that you can cheat.

Oh, you can’t cheat if you want that black, crumbly stuff all gardeners crave; it takes time to make that rich, humusy-smelling substance. Compost like this is the grade A+ soil amendment. It provides nutrients, enzymes, attraction for earthworms, aeration - and it holds water like a charm.

Any organic matter can help your soil do that, though, even if it’s not in the absolute top-notch way completely composted organic matter does. And  a lot of the time, you can scavenge the materials to do it. Which means it’s saving you money, too. (Priced out a load of delivered compost lately?)

If you live in a more rural area, scavenging’s easier, but cities have their own rich supplies.

First, there are the chopped branches and leaves often offered at both city and rural dumps or other sites. After crews clear away branches for power lines, or finish schwoomping up leaves, all that stuff has to go somewhere. In many places, they grind it up in civic grinders and offer it for free. Some places even deliver it.

A few cautions: First, you’d want to be sure you weren’t taking leaves from trees heavily sprayed with pesticides.

And, since it has a lot of woody matter in it, this sort of organic matter is better as mulch. (A friend of mine actually used it for a sort of soft playground surface for her kids.)

Wood takes a while to break down. Some people claim that this changes the acid balance of the soil, or takes up more nitrogen than it offers. I tend to believe the people who say they don’t see much effect from that, and that the value of the organic matter far outweighs any deficits. I feel the same about pine, fir, and cedar needles, other materials that need to stay as a mulch on top until they rot entirely.

If you gather your own leaves, you can pick and choose. In open areas, just go for a spot where there are a bunch of fallen leaves, and start gathering.

Underneath the leaves you will find a darker, moister layer of falling-apart leaves. This is called leaf-mold, and used to be taken into gardens not only for its organic matter, but for its enzymes and mycorrhizal activity, the things that make soil come alive.

Be thoughtful to the trees who are so kindly providing this rich substance: they can spare some of it, but they need it to thrive, too, as does the rest of the plant and fungal community around them. When I gather leaves, I move from spot to spot, and I don’t go all the way down to the soil.

Of course, there are always the leaves from our own gardens, left when the season’s done. All my tulip foliage (after it’s really brown) and dead leaves go into the compost.

And there are the leaves from trees which fall on our own gardens, rotting quietly through the winter, contributing rich, water-saving organic material without any work on our part.

In the city, you might find people who want you to take their leaves - after all, many people pay gardeners to blow or rake or burn their leaves away. Another source of leaves is restaurants. If you can establish a good relationship with a restaurant, and prove yourself reliable in taking away their compost and bringing back buckets, you will have a rich source of leaves. Restaurants that serve a lot of salads or soups are more likely to have leafage, but any place will have some.

Other sources? Horse stables will have plenty of horse manure, which is basically grass or alfalfa held together by other matter, and not at all obnoxious to handle, especially when dry (it’s lighter and easier to haul when it’s dry, too). If you’re willing to shovel it out, the stable owners will often let you have it for free. I’ve also gathered dried horse manure from the fields. Cow manure, too: I’ve found that when cows graze, or are fed alfalfa, their manure is not as hot, especially after it’s been baking in the sun for awhile. You still have to be more careful of it than horse manure, though.

Sometimes feed stores or farms have spoiled hay, hay that’s been out in the rain, and is sold for a pittance. Grass clippings work, but they are so high in nitrogen that they need to be put in a bin so they can burn their heat out. (My grandfather once had me put my arm into one of his triple grass-composting bins. I was shocked at how hot it burned. He proudly showed me the thermometer reading.) You also want to be sure about the provenance of your grass clippings: for some reason, at least in the US, we put our most deadly poisons down where we like our little children to play. Conventional lawn care involves a lot of toxins.

I’m sure there are many more clever places to scavenge organic matter (stuff that isn’t quite, yet, compost).

Wherever you get it, there are a few things you can do with organic matter when you bring it home to the garden.

Of course you can put it in a compost pile and compost it properly, but that isn’t cheating. I’m here to provide you with the easy, cheating ways.

One is to use your organic material as mulch, and let it gradually rot, improving your soil. The barrier of mulch on top is a great way to keep water from evaporating. And the microbial activity of the mulch breaking down feeds your soil, as the mulch gradually turns into lovely, fluffy, composty soil. Soil that holds water just right.

Another method (especially good for soggy stuff like restaurant leavings) is to tuck your organic matter under mulch.

This is the Ruth Stout method, politely called “sheet composting”. (When she first started composting this way, she didn’t hide the garbage under the compost, and concerned friends started wondering if she’d got a screw loose.)

Of course you can’t use the Ruth Stout method unless you have some mulch to begin with. If you used municipal wood chippings, for instance, the mushier vegetable leavings would start to condition your soil immediately for better water retention, while the wood chippings made a barrier, keeping moisture in.

The most labor-intensive method of dealing with compost is, of course, the one that gets the quickest results: tilling it in.  Tilling in requires muscle power and/or machinery, plus being picky about your compostables, so you don’t end of with chunky, hard-to-work soil.

If you have reasonably decent soil, you can also use the compost to build a new bed, using the cardboard method described in the last post.

Whichever method you use,  your soil will hold more water, and get better at holding water (and delivering nutrients) with each passing year.

 Well-aerated humus-filled container soil makes it easy for this tulip to emerge and flourish

It’s not a glamorous subject. But sometimes, you just have to get down to dirt.

The kind of soil you have is a big decider in how much water you use. Not to mention how well your plants do. Last June, I gave out ideas on how to make container soil ideal for conserving water. I still use those methods, and they still work.

But if you have a big garden, in the ground, a lot of those container methods just aren’t practical, unless you want to pay the big bucks to have your entire garden’s soil trucked in, pre-mixed. Or do it yourself, a task that puts you in superhero league.

Some container methods might work in a big garden: for instance, adding earthworms to your soil is an excellent idea in containers and out. By running it through their digestive tracts, earthworms turn soil into something more humusy, nutritious, and aerated. Humusy and aerated is ideal for conserving water; it means your soil structure is the perfect structure for holding water and delivering it to plants.

If you have time, you can actually accomplish a lot of this by earthworms alone. One way of making a garden bed is to lay cardboard, covered with straw or leaves or whatever organic matter you have a lot of, over the patch of ground you want to work next year. In our warm-winter climates, it’s best to do this in the fall; by spring, the ground is likely to be workable, unless it’s a patch of decomposed granite. Even earthworms can’t perform miracles.

This high mountain soil is pretty much all decomposed granite. No earthworm action here, and laying on cardboard wouldn’t make it different

The cardboard forms a moisture barrier, the rotting straw or hay provides organic material, and all this is like hanging out a free lunch sign for the earthworms, who come from far and near to compost and digest.

How can you tell whether this method will work in your soil? The easiest, most ancient test, is to pick up a moist (not wet) handful, and squeeze.When you open your hand, the soil will do one of two things. It can break up, which means you’ve got sand or other types of decomposed rock. That means earthworms are not likely to gather around unless you give them more encouragement than a little cardboard and straw.

If the soil stays in a palm-shaped clod, that means there’s clay or silt in there, in which case, you go on to the second test.

The second test is just to take your thumb and tease out a ribbon from the soil in your palm. If the ribbon is shorter than an inch (2.5 cm) when it breaks, that means you have a lot of sand. If it makes a ribbon 1-2 inches (2.5-5cm) long before breaking, you’ve got soil with some clay and some organic matter. Longer ribbons mean clay combined with sand or silt (the very fine soil from waterways).

There are many more variations and shades to this test, but this is enough to let you know how much water your soil will use.

Basically, it works like this: sand has the biggest particles. Unless those particles are filled with clay (the dread cement-like sandy clay), the spaces between the particles form air chutes that water runs right through. That means plants barely get a taste of water before it runs on by, down into the secret crevices of the earth. Nutrients get washed down, too.

Silt’s particles are medium-sized. Silt is formed by  water-worn minerals, and acts a lot like sand in the soil - except that its particles are smaller and it has more available nutrients. In your garden, silt will hold water and nourish plants, but it will also form flat plates which resist water by forming a barrier.

Clay has the smallest particles, which means water seeps through slowly. Clay also has a negatively-charged ions that hold on to water and nutrients, giving your plants a wide range to absorb. The problem there is that plants need air as well as water, and the small clay particles don’t allow that. While some plants are adapted to grow in clay, a lot of garden plants get stunted in pure clay, and it’s very hard to work.

The ideal soil, which almost no one has, is a combination of all three, called loam. This is the soil that can feed your plants, and retain water without turning into a swamp. Everyone wants loam, and few people have it.

But wait - there is a solution. A savior. A panacea.

Organic matter.

Tune in for our next post: Paydirt: Organic Matters

Do any of you  feel mushrooms don’t belong in a garden? Read any book or catalogue by Paul Stamets, and you’ll learn that mushrooms are already in your garden, in the form of mycorrhizae in the soil.

The word ‘mycorrhizal’ means root fungus (mykes is Greek for fungus, and rhiza is Greek for root). Mycorrhizae are the prefruiting stage of certain kinds of mushrooms: tiny, threadlike webs networking their way through every healthy soil, an enormous microscopic (I always wanted to use those two in a sentence together) network which protects plants from disease and allows them to send nutrients and water to each other, according to need. The Fungi Perfecti catalogue says that plants connected to this network also take up several hundreds or thousands of times more water and nutrients than they do without mycorrhizae. (Fungi Perfecti is the business side of  Stamets’s mushroom venture, and helps fund an incredible range of research and teaching.)

All over the world, underground networks of mycorrhizae keep life afloat. Forests are dependent on thriving mycorrhizae. Without them, we have no healthy plant communities. Without healthy plants, we have no air to breathe and no food to eat. So these microscopic beings  are very important parts of our lives. We may have to broaden our views of organic life to fully understand the world of fungi, which is also our world. **

Unfortunately, industrial land-clearing and farming methods kill off these invisible, vital members of our plant communities. The best thing would be to think about better ways to do our clearing and farming, so we preserve our local blends and varieties of mycorrhizae.  But meanwhile, we can start remediation in our gardens, by buying jars or packets of powdered mycorrhizae blends, and mixing them into our soil, starting a new network.  Or we can get fertilizers with mycorrhizae in them, which is how I got my own introduction to what mycorrhizae can do in a garden.  Suddenly my container plants looked fuller, greener, happier, and they seemed to take stress better, too. I’ve grown invisible fungus ever since.

But Stamets doesn’t just want us to have microscopic underground mushrooms. He’s also a missionary of big mushrooms in gardens. We can naturalize medicinal and edible mushrooms in woodland gardens, and grow edible mushrooms in with our vegetables: Garden Oyster mushrooms (Hypsizygus ulmarius) unlock nutrients from organic debris to feed underlying plants -and they’re reportedly delicious to eat. (I buy another species of oyster mushroom to cook with, and they have a lovely mild flavor and tender texture.) We can also grow mushrooms as a crop, establishing a morel patch (it can take a few years), or growing King Stropharia (Stropharia rugos-annulata), a mushroom that thrives in a huge range of temperatures on waste products like sawdust and wood chips, and fruits delicious mushrooms as big as five pounds.

Growing mushrooms in our gardens is a huge innovation in mushroom culture, which often requires painstaking and esoteric methods to work. A local mushroom grower once told me that he had to imitate thunderstorms in his mushroom growing area, so his mushrooms would fruit. Other typical mushroom-culture equipment includes sterile growing rooms, agar cultures, and matching the right growing media and techniques to each mushroom variety.

Growing Gourmet and Medicinal Mushrooms goes deep into the strange cultures of the mushroom world, and it is here that we find out some of King Stropharia’s weird, secretive habits. King Stropharia mushrooms are bountiful, beautiful, and delicious, Stamets starts off, giving a few informal recipes to show he really enjoys them, and isn’t just talking theoretically. But he also reveals a deeper layer of the generous stropharia personality: eating them for more than two or three days in a row suppresses the enzymes we use to digest them.

For those who don’t understand how this might be a problem, Stamets offers a cautionary tale. A friend of his became enchanted by the mushrooms, once they were introduced: he grew them, ate them frequently, made new recipes for them. At last he culminated his love by throwing a huge summer garden party for King Stropharia, so that all of his friends would know the mushroom he honored with his love. He indulged that love privately also, eating the mushrooms as he cooked; by the time of the party, he had been partaking of King Stropharia for three days. While his other guests enjoyed the succulent fungus, he became violently ill. “To this day, he now views King Stropharia (and me) with great suspicion,”  Stamets concludes. (pg. 338)

The mushroom at the top of this post was growing in the woods near my house.  It’s probably edible, but all I could figure out is that it’s some kind of bolete, narrowing  it down to a few thousand choices. It’s certainly past its prime, as you can tell by looking at the yellowing drying spongy bit (my mushroom botany is pretty primitive) underneath the cap.

I have been on a few local mushroom hunts, but I don’t trust myself to identify more than a few varieties. I don’t play around with mushrooms. It could be deadly, or at least really sickening. My hope is that by going on more hunts and hanging out with mushroom hunters, I’ll build my mushroom vocabulary. Another way I hope to improve my mushroom knowledge is by cultivating them. That way, I can be sure of the variety, and learn more about the different forms of each mushroom.  I’ve already ordered some plugs and a kit of different mushrooms. I’ll be reporting more later.

*My title is derived from the title of one of Eleanor Cameron’s whimsical 1950s science fiction books,  The Wonderful Flight to the Mushroom Planet, available through Fungi Perfecti. Her books are supposed to be juvenile fiction, but they’re  fun for older juveniles, too.

**For an impassioned and thorough explanation of the mycorrhizal network, take a look at the Las Pilatas Nursery site.

 This young pine is growing out of an inch or two of granite dust, and pure granite. The red plant next to it is a succulent, probably Sedum obtusatum, a stonecrop.

There’s something elemental about high mountains. Everything’s stripped down.  Rock. Plants. Water. It’s a perfect place to see how soil begins.

As far as I know, soil starts in one of two ways: things rot (usually plants), or rock breaks down. Usually, both are going on at once.

Rock breakdown is slow; we rarely think of it in our gardens at home. But it must be the original place where soil starts. In many of the places where we garden, the rotted plant matter has accrued so much that the soil obscures the place where it came from. (Although in many places where I’ve gardened, the rock layer was not all that far below the soil, and needed breaking up with a pickaxe.) In the mountains, extreme climate and topography mean that soil-making is always in its infancy.

On bare mountain rock, threadlike parts of lichens make a strong acid which breaks down granite, feeding the lichen. High mountain conifers can grow in just a tiny bit of this crushed granite. They then break up more rock with their roots, drop needles and eventually wood which rot and make more soil, so that other kinds of plants can grow there. Animals feeding on the plants do contribute organic matter one way and another, but the bulk of rotting material is plants.

This is the same pine tree as in the picture at the top. This is its root, going straight into crushed and solid granite.

This juniper root gets its nutrients the same way, and has become a large tree.

This dead tree has helped create a small plant community around its roots. It will soon fall over and add to the soil by rotting. Probably rain will wash a great deal of its rotten wood into the lake below, but some will stay in flat places and crevices along the way.

Reference:

Tracy I. Storer and Robert L. Usinger, Sierra Nevada Natural History, University of California Press, 1963. (They have recently come out with a more recent version, but this is the one I own and still use.)