Cheyenne Garden Gossip

Gardening on the high plains of southeastern Wyoming


Soil microbes better than rototilling

2017-05Lowenfels-Endomycorrhizal fungi

Endomycorrhizal fungi spores are ready to grow into plant roots, carrying nutrients and moisture. Photo courtesy of Jeff Lowenfels.

Published May 7, 2017, in the Wyoming Tribune Eagle, “Soil microbes, no rototilling key to next generation of gardening”

By Barb Gorges

Twice in the space of a month this spring I heard rototilling renounced for the sake of keeping soil microbes healthy.

One speaker was Jeff Lowenfels, garden columnist and author from Alaska who spoke at the Cheyenne Botanic Gardens/Laramie County Master Gardener spring lecture series. The other was Ron Godin, recently retired extension agronomist in western Colorado, speaking at the Wild West Gardening Conference in Cheyenne.

There are a billion microbes in a teaspoon of healthy soil. The interactions of the whole community of microbes is a giant web of who eats whom and who feeds whom.

Basically, decaying plant material feeds microbes and in turn, microbe “excrement” feeds plant roots.

Microbes include nematodes, bacteria, fungi and protozoa. There are some bad actors, but in general, everything balances and plants grow. For example, prairies and forests have self-sustaining soil microbial communities—no synthetic, chemical fertilizers or pesticides are required.

But when European farmers landed in the New World, they opened things up with the plow and have continued to plow ever since. Regular plowing (or hoeing or rototilling) disrupts the soil microbes. They can’t do their jobs. Farmers repaired damage somewhat with applications of manure and compost. But then came the 20th century’s inventive use of nerve gas left over from World War I as insecticide, and leftover nitrogen-based bomb-making materials from World War II became the perfect fertilizer.

Except that it wasn’t healthy for the microbes.

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Ectomycorrhizal fungi grow close to the surface of roots and grow webs around them carrying water and nutrients. Photo courtesy of Jeff Lowenfels.

Synthetic fertilizers starve the microbes in a way and pesticides kill off beneficial organisms, causing the need for a never-ending cycle of synthetic fertilizer and pesticide application. This was great if you owned stock in the large chemical companies, but bad when you understand the side effects including health issues animals and humans—especially farmers, because the chemicals get into drinking water and food.

 

Lowenfels happily dispensed advice on garden chemicals for years until someone sent him two electron microscope photos, one of a fungus that had trapped a root-eating nematode, and the other of a nematode happily chomping a tomato root unimpeded.

In the first photo, the plant was secreting a substance that attracted the fungus, which in turn attacked the nematode. In the second photo, the fungus was missing due to the use of synthetic fertilizers and pesticides.

After his conversion, Lowenfels wrote three books. He said the essential one is “Teaming with Microbes, The Organic Gardener’s Guide to the Soil Food Web,” coauthored with Wayne Lewis. You’ll notice the play on words in the title–healthy soil is teeming with microbes, and you’ll be teaming with them.

Put away the rototiller

First, put away your rototiller. It’s still handy if you are turning your lawn into a pollinator garden, but otherwise, annual rototilling is detrimental to the soil microbe community. Godin said this advice translates to farming as well.

It will take time to undo the cultural tradition of breaking soil down into a fine, clump-less and smooth expanse of dirt. But there are two reasons for disturbing the soil as little as possible, even in a vegetable garden.

First, every time you dig into soil, you bring up weed seeds, most of which require light to germinate. You just made more work for yourself. Cut weeds off at the soil surface rather than digging them.

Second, microbes feeding your plants and fending off bad stuff can’t function if you break them up. Keeping them intact means less work for you, less fertilizer spreading, less watering since healthy soil holds water better. Pesticides are a last resort for serious problems. Re-inoculate your soil with microbes soon after.

In windy Cheyenne, there’s also a third benefit to not tilling your soil into fine dust: microbes “glue” things together and the resulting clumpy soil doesn’t blow away.

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In this electron microscopic view, Glomalin, stained green and coated with spores, is produced by a group of common soil fungi. It coats soil particles like super glue, sticking them together in clumps. Photo courtesy of Jeff Lowenfels.

To plant seeds or transplants, make an opening just large enough. The roots will find their way without the soil being “fluffed.” Healthy soil has lots of air spaces already. Then mulch.

 

Godin’s rule is 100 percent cover, 100 percent of the time. Cover for large gardens or farms could be annual cover crops later mowed to form mulch. In small gardens use leaves, grass clippings and compost.

Replace chemical fertilizers

In the years chemical fertilizers have been around, studies show fruits and vegetables have dropped in nutritional value. It’s due to the missing micronutrients soil microbes used to pull from decomposing plant material and mineral soils. Synthetic fertilizer is incomplete.

Traditional organic gardening recommends digging compost into the soil, but  Lowenfels says digging breaks up the soil community. Better to side-dress plants, leaving the compost (or mulch) on the soil surface where microbes will get at it and break it down. It works on the prairie and in the forest—there’s no 100-year-old pile of dead grass, leaves or pine needles.

Lowenfels said there are three different groups of plants in your yard. Perennial flowers, shrubs and trees want their nitrogen in the form provided by fungally dominated soils. The compost that promotes this is the brown stuff (mixed with a little green): dry leaves, bark, wood chips, twigs, branches—like the forest floor.

Annuals, including vegetables, prefer their nitrogen produced by bacterially dominated soil. This is green stuff (with a little brown), grass clippings, freshly picked weeds (without seeds) and fruit and vegetable kitchen scraps.

The prairie, like your lawn, falls in between. It appreciates finely shredded brown fall leaves and thin layers of green grass clippings.

Brew compost tea

Compost tea, compost soaked in water, is another way to inoculate your garden with microbes and feed them too. If compost and compost tea smell ugly, that’s anaerobic activity. You need aerobic activity—more air.

Lowenfels gives directions for making a bucket into “a simple actively aerated compost tea brewer using aquarium pumps and air stones.” Fertilizing your plants, and yes, your houseplants too, is as easy as watering them.

While chemical companies made their fortunes keeping our soils addicted to their products, new companies are offering to aid us in bringing our soils back to health. They are building better compost tea brewers. Labs can estimate your microbe population. Our local independent garden centers will sell you mycorrhizal fungi in powdered form you mix with water.

This new era of catering to microbes has gone mainstream. Lowenfels reported that at the 2016 Garden Writers of America conference, none of the tradeshow vendors was pushing synthetic fertilizers or pesticides.

For the last 35 years, my husband, Mark, and I have cared for our lawn and garden without a rototiller or synthetic fertilizers and pesticides. We mulch the garden and use natural lawn fertilizers. I look forward to adapting Lowenfels’ ideas to step it up.

[If you are also adapting to the new era in gardening, let me know how it is going. Contact me at bgorges2 at gmail.com.]

More information:

Besides “Teaming with Microbes,” his first book, Lowenfels has also authored:

–“Teaming with Nutrients, The Organic Gardener’s Guide to Optimizing Plant Nutrition”

–“Teaming with Fungi, The Organic Grower’s Guide to Mycorrhizae.”

 

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Starting from Seed: Choosing the Right Seed

Short season seeds

Some short growing-season vegetable choices for Cheyenne

Published Feb. 26, 2012 in the Wyoming Tribune Eagle, “From scratch: A beginning gardener shares her experiences gained from taking the first steps in growing indoor tomato plants from seed.”

By Barb Gorges

Can I call myself a gardener if I buy blooming bedding plants and keep them alive until frost?

Possibly. But my real test is whether I can start something from seed indoors, which I haven’t done in 20 years. And, even though it’s February, now is not too early to start thinking about that.

My inspiration is the pep talk Kathy Shreve and Barb Sahl gave the Master Gardeners’ class recently. It looks so simple: florescent shop light, sterile seed-starting medium and pots, proper watering, a little air circulation and fresh seed.

Seed. There’s the sticky spot. Some plants I like don’t do well in Cheyenne or would need more sun than my shady yard offers.

This is my experiment for the coming growing season: raise from seed at least one easy annual flower and a fast tomato.

Why all the bother? Because just as I can bake my own bread, even though it’s much easier to buy a loaf at the bakery, I want to see if I can grow from scratch.

Seeds

There are several seed companies out there that cater to our unique gardening needs.

For starters, I was already familiar with Maine’s Pinetree Garden Seeds. This company offers a reasonable climate match. I ordered from them years ago and Shreve does today. Visit www.superseeds.com or call 207-926-3400.

Shane Smith, director of the Cheyenne Botanic Gardens, mentioned three seed catalogs recently that match other aspects of our challenging growing conditions.

For high altitude, try Seeds Trust, located in Littleton, Colo., www.seedstrust.com, or call 720-335-3436.

For drought-hardy plants, High Country Gardens in Santa Fe, N.M., offers recommendations on xeric gardening, as well as plants and seeds. Visit www.HighCountryGardens.com, or call 800-925-9387.

For a comprehensive flower and vegetable catalog, check Johnny’s Selected Seeds, which is another Maine company. Visit www.johnnyseeds.com or call 877-564-6697.

You can also check local garden centers, but do read the seed packets carefully.

Unfortunately, I don’t think anyone specializes in plant varieties that are hail and wind resistant.

Planting strategy

For my summer project, Wissner recommended I start with a cherry tomato plant. The fastest tomato I could find, maturing in 55 days, is called Gold Nugget, which produces yellow cherry tomatoes.

Local gardeners who want to grow tomatoes might want to look for tomatoes that mature in 55 to 60 days, she said. This means with luck, you’ll harvest your first tomato 69 to 80 days after May 25–that is, between Aug. 2 and 13. The average first frost date looms barely more than a month later, about Sept. 20.

Why all the extra time? Vegetable seed packets and catalogs will tell you how many days it takes for seeds to germinate and how long until harvest time. In reality, you need to extend those time frames by many days, Wissner said.

When Wissner starts vegetables indoors, she first adds another 14-20 days after germination to allow plants to grow to transplant size.

She then adds another 14 to 20 days after transplanting outdoors. That accounts for transplant shock. At that point, she can start counting the stated days to maturity.

For my annual flower, Wissner recommends cosmos, which produces brightly colored flowers.

The cosmos I’ve chosen, a dwarf variety in a mix of colors, germinates in seven to 10 days. Maturity is at least 75 days for some cosmos varieties so if I want flowering plants to put out in May, seeding indoors the first of March might not be too soon to start. But since even dwarf cosmos could be 2 feet tall at flowering, they’d get too big for my set-up, so I’ll wait a bit.

And both the flowers and the tomato will need “full sun,” –at least 6 hours per day. I’ll have to think about where to fit them in my shady yard, or which tree to cut.

It’s easy to see why buying well-developed plants from the nurseries is so popular when, for instance, some varieties of tomatoes are rated at 120 days to maturity, the number of days after seed germination before the first fruit can be harvested.

Next month I’ll prepare my seed-starting equipment. Digging in the garden is still months away, even if wind keeps evaporating the snow.

Climate

The first hurdle to choosing plants that will thrive in your yard is understanding the climate.

The newly revised USDA Plant Hardiness Zone Map (http://planthardiness.ars.usda.gov) shows Cheyenne in Zone 5b, meaning our maximum cold temperatures are -15 to -10 degrees Fahrenheit. Because of our 6000-foot elevation and northern latitude, we also have a short growing season.

Cheyenne’s average first frost-free date is May 25—that’s considered a safe time to get your plants in the ground.

After that, the growing season is only 90 to 110 days long, according to Catherine Wissner, University of Wyoming Laramie County Extension Service Horticulturist.

You can see why season extenders like Wall O’ Water, hoop houses or high tunnels— modern, light-weight greenhouses—are popular here. They can push the planting date earlier by weeks.

Note: Using Catherine’s formula and the catalog information, I figure I’ll need to plant the seeds four to six weeks before May 25, in early April. If I decide to try Wall O’ Water, giving each plant its own little protective, water-filled, plastic walls so that I can transplant them earlier, I will have to start seeds earlier.