Lasagna Gardening Simplified

First popularized back in the 1970s, “lasagna gardening” involves piling up thick layers of cardboard and uncomposted kitchen scraps on top of (sometimes) double-dug soil. The practice is touted as a way of removing lawns and improving soil with little work.

Linda Chalker-Scott, Extension Urban Horticulturist at Washington State University, proposes a vastly simpler version of lasagna gardening.  Chalker-Scott suggests skipping the double digging, cardboard and kitchen scraps. The double digging disrupts soil texture, the cardboard interferes with water penetration (I know this from experience) and the kitchen scraps create a plant nutrient overload. Instead Chalker-Scott suggests simply a very thick layer of mulch–12 inches.

Mulch is often free, as many cities give it away, and it does wonders for the soil. Mulch, in fact, breaks down into soil, retains moisture and creates habitat for earthworms.

Read more in Chalker-Scott’s post, “Is lasagna gardening really worth the effort.

Geoff Lawton Soils Video

Help, I’m turning into a soil geek. I just spent an evening viewing a video entitled Soils featuring permaculturalist Geoff Lawton.

What I like about this video is that it’s not just about soil, but Lawton actually shows you what you can do to improve your soil. In the DVD he demonstrates how to build a compost pile (lots of carbon material), contoured vegetable beds, a compost pile heated shower and a simple vermiculture system using an old bathtub to name just a few projects. You get practical tips in a professionally produced DVD. Here’s a trailer:

Soils is available for around $40 US on the Permaculture Research Institute of Australia website, which also has an interesting blog. In an email the Institute said that they allow educational screenings of Soils as long as you don’t charge admission. So get some friends together, watch this video and then go shovel some manure! It would also make a nice addition to a school library.

Thanks to Scott Kleinrock of the Huntington Ranch for the tip on this one. Scott said the Geoff Lawton Food Forest DVD is also worth viewing.

UMass Soil Testing

I finally got around to trying out the University of Massachusetts’ soil testing service and can report that it’s fast and cheap. I tested two areas of my yard for both nutrients and heavy metals and found out, more or less, what I expected, that I need to add a small amount of nitrogen. Surprisingly, for having such an old house, I don’t have a lead problem. It costs just $9 for the basic test and $13 for the basic test + heavy metals. The order form and instructions can be found at http://www.umass.edu/plsoils/soiltest/. Why test? UMass sums it up nicely:

  • to optimize crop production.
  • to protect the environment from contamination by runoff and leaching of excess fertilizers.
  • to aid in the diagnosis of plant culture problems.
  • to improve the soil’s nutritional balance.
  • to save money and conserve energy by applying only the amount of fertilizer needed.
  • to identify soils contaminated with lead or other heavy metals.

The brochure they send with the results is geared towards New England soils, but beggars can’t be choosers. This test is a bargain, but I’d check first with your local extension office to see if they offer free or low cost soil testing first. Should you want the Cadillac of soil tests, vegetable gardening expert John Jeavons recommends Timberleaf Soil Testing. I’ve seen some Timberleaf reports and they are quite detailed and informative.

The cutting edge of soil testing is about the living inhabitants of the soil, all those microorganisms, fungi and other critters rather than just old “NPK.” Dr. Elaine Ingham is a pioneer in this field. She offers “Soil Foodweb” testing via her website. I’ve read some grumbling from academics about some of her ideas and her commercial endeavors, particularly related to aerated compost tea. However, soil foodweb testing makes intuitive sense to me, though I have not tried it. You can read her interesting Soil Biology Primer here, and make up your own mind. There’s also an excellent book based partially on her research, Teaming with Microbes: The Organic Gardener’s Guide to the Soil Food Web.

Thanks to Cool Tools for the tip on UMass.

A Cheap Soil Testing Service

I’ve started a new method in the garden: test the soil, amend according to the recommendations and grow. Lather, rinse, repeat. In many parts of the U.S., you can get free or low cost soil tests from your county extension service, but not here in Los Angeles. Some time ago I answered a reader’s question about where to get soil testing done, only to have to correct my response several times. Last week, Homegrown Evolution pal and the editor of Cool Tools, Elon Schoenholz, gave me a definitive answer on where to send soil for testing: the University of Massachusetts Amherst, Department of Plant and Soil Sciences Soil and Plant Tissue Testing Laboratory. A standard soil test is $9, $4 more for the standard test plus organic matter. The standard tests includes heavy metals. That’s a bargain, and you don’t have to be a resident of Massachusetts. They also offer compost, fertilizer and plant tissue tests at reasonable prices.

Read a review of UMASS soil testing by master gardener Amy Thompson at Cool Tools.

The Homegrown Mailbox: How and Where Do I Get My Soil Tested?

When you write a book you get questions. In our case, due to the sinking economy in California, they are delivered by Kevin Costner on horseback rather than by email or regular federal postal trucks. No problem, we like questions. A caveat here: like Nancy Klehm, the Green Roof Growers and Black Swan author Nassim Taleb, we prefer the term “practitioner” to describe what we do as opposed to “expert”. We favor experience over speculatifyin’ and make no claims to accuracy. But, we’re happy to take the letters from Kevin, the horse poop for compost and try our best. Here’s one question we get a lot:

Q: Y’all know where I can get my soil tested? I’ve started HUGE garden in my side yard and it just occurred to me that it is where people used to park their cars. I’m concerned about Oil or other pollutants from the cars that might still be in the soil. Any experience with this? Can I test without it costing an arm and leg?

J.R., Los Angeles

A: See my updated response here. [Note update at bottom of this post!] There’s basically two groups of things to test for: contaminants and soil nutrient levels. There are cheap home test kits, but sending samples to a lab is much more accurate. To find a lab in the US, the best place to start is with your local Cooperative Extension Service. Find yours via this link. Some offer free or low cost soil testing.

Here in Los Angeles the Extension Service does not offer testing, but they were nice enough to provide a list of local labs. The lab I talked to, Wallace Laboratories, offered tests at $75 a sample–see their price list for specifics. Before you send a sample talk to the lab to find out what they test for and how much they charge for phone consultation in interpreting the results. If you’re worried about contaminants make sure to describe your situation.

Sampling is a DIY project. You put the soil in a bag and send it off to the lab (they’ll tell you how to dig for the sample and how much to send). You’ll probably need to do several samples since different parts of the yard might have different problems.

In the end I cheaped out and went with Peaceful Valley’s soil testing service for $29.99. No contaminant testing, but the results did tell me that I’m very low in nitrogen, with a soil ph that’s slightly alkaline. They charge for phone consultation, but I was able to interpret the results myself with their slightly overpriced booklet that you can order along with the test.

Another approach, especially if you live in an old house like ours, is to assume that your soil is contaminated, skip the test, and grow things in raised beds, containers or stick to ornamentals. You could also try bioremediation: each season plant a cover crop, let it grow, and then pull it up and dispose of it. Test the soil until it comes out clean. This works well, but it can take many years to get all the contaminants out.

For those of you in Los Angeles, our local Extension Service agent Yvonne Savio kindly sent me the following list of labs with comments.

Biological Urban Gardening Service
PO Box 76
Citrus Heights, CA 95611
(916) 726-5377
URL: www.organiclandscape.com
Email: [email protected]
Organic recommendations, very user-friendly
Owner Steve Zien and I co-author “Organic Matters” organic gardening column in Sacramento Bee for 20 years.

Wallace Laboratories
365 Coral Circle
El Segundo, CA 90245
(310) 615-0116
www.bettersoils.com
Test results very scientific
No recommendations

Soil and Plant Laboratory, Inc.
1594 N. Main Street
Orange, CA
(714) 282-8777

FGL Environmental
853 Corporation Street
Santa Paula, CA
(805) 525-3824

USDA Natural Resources Conservation Service
44811 N. Date Avenue
Lancaster, CA 93534-3136
(661) 945-2604

Here’s a dirt cheap (pun intended) test for soil ph that you can do yourself.

UPDATE: 7/7/09: Visiting journalist Michael Tortorello tipped us off to the University of Minnesota’s soil testing lab will test out of state samples for their regular (low) fee. It’s much cheaper than the services listed above. Their submission forms are located here.

  • Page 2 of 2
  • <
  • 1
  • 2