It’s spring in Minnesota and that means male frogs and toads are out singing sweet songs to all the ladies. My husband Mike and I were fortunate enough to come upon a wetland filled with song the other day while on a walk with our dog, Lily. We recorded what we heard and posted it so you can enjoy it too.
A few weeks back I did a short presentation in Pine City, Minn., on how to build good, healthy soil, and a woman in the audience asked: “How do I know if the compost I’m using is safe?”
I’ve been wondering that same thing, I told her, explaining that I’ve been researching the topic so I have some answers, but many more questions, too. This prompted more people to weigh in on the subject, asking: Was it important to use organic compost, especially when growing edibles? How do you know that even organic compost is safe?
Does composted manure from conventional farmers contain pesticide and herbicide residue that could cause problems in their gardens? Should you have compost tested to find out what’s in it before you use it on food crops and, if so, where? And what about GMOs? Is it safe to use composted manure produced on conventional farms on which cows eat things like Monsanto’s genetically modified Roundup Ready corn and alfalfa?
Complex questions like these are difficult to answer definitively for a lot of reasons. Sometimes, there aren’t many studies, if any, on a particular topic. Or maybe there are numerous seemingly reputable studies, but many of them conflict with one another. For example, as a journalist who interviews people for a living, I can tell you that for every scientist I’ve talked to who dismisses the French study that came out last year linking a genetically-modified strain of maize to huge tumors in rats, I’ve got another scientist saying the study should be given serious consideration.
Compost may sound like a simple enough topic, but like so many things it is complicated by money, politics and personal biases of all persuasions. And so, fellow gardeners, I think the best we can do here is take a look at the science that’s available and make the best informed decisions we can. This is the first of several columns I plan to write on compost in an attempt to answer some of the questions above, and others that will no doubt come up. Let’s start with a little background.
Look for an OMRI label
Organic compost is probably not necessary for all of your gardening needs, but a lot of gardeners, including me, like to use it for edible crops. But what does organic mean, exactly? Compost is by its very nature organic, so an “organic” label doesn’t necessarily tell you a whole lot.
If you’re looking for organic compost, for example, that doesn’t contain sewage sludge and other things that are precluded by regulators, look for an OMRI label on the packaging. This label, from the Organic Materials Review Institute, means that the product has been reviewed and approved for use in certified organic production. You’ll find a list of OMRI-approved soil amendments here.
Does it meet NOP standards?
Compost does not necessarily need to have OMRI approval to be used by organic farmers. In the U.S., the National Organics Programs (NOP) sets the standards for compost. Those standards basically cover what the compost can and cannot contain (like, no sewage sludge or urea), carbon to nitrogen ratio, how often piles must be aerated and how many days the pile must be turned while temperatures are kept between 130 and 170 degrees Fahrenheit (which kills weed seeds and disease-causing pathogens).
Certified organic farmers can use compost that meets NOP standards even if that compost was produced on a conventional farm. That’s because NOP regulations do allow low levels of synthetic substances, including synthetic pesticides and herbicides. The explanation being that, realistically, we live in a polluted world and some level of environmental contamination is unavoidable. (Go here for a list of what can be used on organic farms in Minnesota.)
Curious about what types of compost local organic farms use, I called Northfield-based Gardens of Eagan, one of the biggest suppliers of local, certified organic produce in the region for more than three decades. They told me they make a lot of their own compost, but they also use Cowsmo, a compost product John Rosenow and his wife Nettie have been selling for more than 20 years. Their business is an offshoot of their fifth-generation conventional dairy farmer in Cochrane, Wis.
Rosenow kindly took the time to explain what he has explained to countless others over the years. No, Cowsmo compost is not certified organic, but it does meet NOP standards and is widely used by certified organic growers in the region. Yes, it really is composted manure from their dairy cows. The cows do eat Roundup Ready corn and Bt-Corn, but the alfalfa they eat is not GMO. (Here is their website’s FAQ.)
Rosenow, who also sells four types of compost-based potting mix used by organic growers, says he hears the disappointment in people’s voices when they call him looking for organic compost. They’d prefer not to buy from a conventional farm, and he gets that. But, once they’ve called around, folks usually call back to order a load because organic compost from an organic farm is in short supply around here. If organic beef farmers have it, they usually need most of it for themselves, he explains. John Middleton, Gardens of Eagan’s operations and field manager, agrees that availability and cost make it difficult to get organic compost from an organic farm in great quantity. So compromises have to be made.
In addition to Cowsmo, Middleton likes Purple Cow Organics’ compost, which is available locally in bags at many garden centers. Cowsmo compost and potting soil can be purchased locally in bulk, totes or bags at several Twin Cities’ locations, including the Wedge Co-op, Mother Earth Gardens and Mississippi Market. If you shop for other types of compost, he advises checking the labels carefully. “You’re looking at what’s in it,” he says. “Don’t buy something that contains things you can’t pronounce or has numbers in it, which would indicate things like dyes and fungicides.”
Stay tuned for Part Two on all things compost. In addition to other things, I’ll be talking about more quality compost products offered by Kern Landscape Resources in St. Paul, Mississippi Topsoils in Cold Spring, Minn., and more.
Most every commercial potting mix contains sphagnum peat moss because it’s a good, lightweight, organic amendment that improves drainage, as well as water retention and air circulation. The downside to peat moss is that it isn’t a sustainable resource. Peat moss is the decomposing remains of living sphagnum moss, and it is harvested at unsustainable rates from bogs in a manner than involves scraping off the top layer of the living moss to get to the saleable product below.
This process destroys centuries-old bogs, doing away with wildlife habitat, releasing C02 into the air, and eliminating wetlands that help prevent flooding. Because of this, conservationists and scientists all over the world have been pushing for limits and even bans on peat moss harvesting.
In Britain, for example, where peat is often burned for fuel, harvesting has become so intense that the government has set goals for phasing out peat for home gardening use by 2020. Professional growers will need to go peat free by 2030. For more information, check out the Royal Horticulture Society’s website: http://www.rhs.org.uk/Gardening/Sustainable-gardening/Peat-and-the-environment/More-about-peat.
Most of the peat used by the horticultural industry in the U.S. comes from Canada where talk of limits and bans is also heating up. So, whether you are concerned about the sustainability of peat of not, now seems like as good a time as any to explore some peat-free potting soil options.
Topping the list of sustainable peat alternatives is coconut coir. Coir is coconut husk fiber, a byproduct of the coconut industry in Southeast Asia where it is largely considered waste. Dehydrated and sold as small bricks or bales, coir can hold nearly 10 times its weight in water. In fact, researchers at Auburn University and the University of Arkansas recently compared peat and coir and found that the two were on par as soil amendments (http://extension.oregonstate.edu/gardening/coir-sustainable-alternative-peat-moss-garden). Like peat, coir is low in nutrients, but it is also less acidic.
You can buy peat-free potting soil mixes, which are slightly more expensive than peat-based blends, and consist primarily of compost, pine bark (or another type of bark) and coconut coir. Some mixes may also contain materials that help to improve drainage such as perlite (a type of volcanic ash) and vermiculite (a mineral that comes with its own set of environmental challenges).
You’ll save money if you make your own peat-free potting soil. And it’s easiest to buy your ingredients and mix them in a wheelbarrow before filling your containers. Here are a few recipes that are easy, affordable and still offer good drainage.
For seed starting:
Wet coir according to package directions and use it as you would peat in trays or other containers.
1 part compost
2 parts coconut coir
1 part builder’s (sharp) sand
For ornamental plants:
1 part coconut coir
1 part compost
1 part good garden topsoil
1 part builder’s sand or perlite
2 parts compost
2 parts coconut coir
1 part builder’s sand
Keep in mind that compost makes a good slow-release fertilizer. But container-grown plants, especially edibles, will need additional nutrients throughout the season. Some good choices include: additional compost, bone meal, feather meal, vermicompost (worm poo), fish emulsion, cottonseed meal and alfalfa meal. Earth-friendly fertilizer blends can also be purchased by the bag. I particularly like some of the organic products offered by Espoma.
People have been talking about straw bale gardening for years and, I admit, I haven’t really paid much attention. It’s not that I wasn’t curious about the idea. It just wasn’t on the top of my list of things to try until recently when I got the opportunity to talk with Joel Karsten about his new book Straw Bale Gardens: The Breakthrough Method for Growing Vegetables Anywhere, Earlier and with No Weeding.
Karsten isn’t just another gardener talking about straw bale gardening. He invented straw bale gardening. That’s right; he came up with the idea for a growing technique that has now become an international sensation. And it all started when he was a kid growing up on a farm right here in Minnesota.
Farmers, he told me, have no need for piles of wet, unruly straw. So when a bale would break open for one reason or another and get rained on, his family would push it up against the barn to break down over time. “I always noticed that those stacked up, broken bales would have the biggest, tallest weeds growing out of them, so I knew there was nutrition in there,” Karsten recalls, adding that he didn’t think much more about it until 15 years later.
By then, he had earned a bachelor’s degree in horticulture from the University of Minnesota, and he and his wife Patty had just bought a house in Roseville. After looking forward to gardening at their new home, they were disappointed when they realized that their whole lot consisted of little more than construction debris in which nothing was going to grow well. Then, Karsten remembered those straw bales. “And I thought, what if I just line those bales up and try growing vegetables in them as they decompose?” he recalls.
An idea takes off
Karsten ran the idea by some of his former professors, but they were nonplussed. So he called his dad, hoping for encouragement. “Well, let’s try it. What’ll it hurt?” his dad said. (If only everyone could have a parent like this.) The two of them started their straw bale gardening trials the very next weekend, and Karsten began taking detailed notes on everything they tried.
Not surprisingly, all those straw bale gardens attracted a lot of attention on the family farm. Finally, tired of explaining what in the heck they were to everybody who came by, Karsten’s dad asked him to write up a handout that he could give to people. Over the years, that handout evolved into a booklet that grew fatter and fatter and was purchased online by thousands of people who visited Karsten’s straw bale gardening website: http://strawbalegardens.com. Publishers began contacting him, and the result is his new book, which was just published by Cool Springs Press.
Why try it
Straw bale gardening is a great option for gardeners who have poor soil, a small amount of space, limited mobility or just an insatiable curiosity to try new things. As the book explains, bales can be placed on the ground to become instant raised beds—even in a parking lot. But they are more than containers. As the bales decompose, the organic matter provides nutrients to the plants inside. In addition to holding water well, straw bale gardens don’t need to be weeded and have fewer pest and disease problems. Another advantage is the ability to start planting earlier in the spring. New straw releases heat as it decomposes, helping seedlings get established faster than they could in regular garden soil. “Vegetables like to have warm roots and cool tops,” Karsten explains. “So having the inside of the bale be warm in the spring means you get early root establishment very quickly.”
How to do it right
It’s not hard to grow vegetables and annuals in straw bales. But there are some make-or-break tips that Karsten has learned over many years. He shares all of his know-how in his book, which includes lots of beautiful, helpful photos and planting schematics. Those who want an in-person demo can attend one of Karsten’s many straw bale gardening talks this season.
Dates and times can be found on his website, but I want to call out Straw Bale Gardening Day at the Minnesota State Fairgrounds on Saturday, April 27 from 9 a.m. to 2 p.m. Karsten will do a short talk at the start of every hour in the parking lot just north of the main entrance. Straw bales will be available for purchase (and can be delivered), and he will also be selling books. Be sure to check out his demonstration garden so you can see exactly how to try straw bale gardening at home. Count me in!
I admit it. I have Home and Garden Show envy. I read blog posts by gardeners all over the world who talk about the innovative gardening products and to-die-for plants they just saw at their local Home and Garden Show. (Most of them post great photos, too, so I don’t think they’re lying.) Inevitably, their exuberance makes me feel excited about going to Minneapolis’ Home and Garden Show, which is ridiculous because I already know that our local show is totally lame. Lame, lame, lame! Year after year, I go because I get free tickets with a garden magazine I subscribe to. And every year I walk away complaining about how lame it is that people have to pay $11 per ticket, $13 at the door, to walk around a hot, windowless arena packed solid with trade show booths offering the same array of stuff: granite countertops, gutters, expensive kitchen gadgets, hideous bathtub and shower inserts, outdoor gazebos, patio furniture, flooring and hot tubs. So many hot tubs—$16,000 hot tubs.
Seriously, they should pay people to attend this event. Or at least let people in for free: the hope being that once they’re inside folks will buy some mini doughnuts and cheese curds followed by copious amounts of beer. Enough beer to, say, allow them to throw down a credit card for a hot tub as big as a Volkswagen. “Ah, who the hell cares where we’ll put it, honey. Let’s just get it!”
Okay, if you’re not a local, you’re probably thinking: “Hey, it’s not like anyone is holding a gun to people’s heads to make them go to this home show thing.” But you’re wrong. There is a gun, and it’s called winter. In Minnesota, by the time March rolls around, most of us would pay any amount of money to go anywhere to see anything different than what we’ve been looking at for five months indoors. Add the word “garden” to the name of the event, and you’ve got yourself a crowd. Even people that don’t give a hoot about plants will fork over cash just to see something ALIVE, maybe smell some dirt, see some flowers. We are a desperate lot.
But therein lies the problem. There ain’t much Garden in our Home and Garden Show. Yes, there are some interesting gardening talks given by local gardening gurus, as well as some of my fellow master gardeners. But those are usually off in some airless side room far from the arena’s main floor. To see actual plants you have to thread your way through countertops and hot tubs and super-absorbant sponges to get to one small area in the back of the arena where mostly lesser-known landscape design firms have their displays. Some years are better than others. This year, though, was just plain weird. For reasons I am completely unable to fathom, there seemed to be some kind of TV show theme to the booths. This would have been bizarre no matter what, but why Fantasy Island, Miami Vice and Gilligan’s Island? Did the organizers of this event swear off TV in the 1980s? Are the TV shows of my adolescence already so kitschy they’ve actually become cool?
Were people worried that visitors would be bored looking at some dumb, old plants outside the context of a TV theme? I don’t get it. Do you?
So, tell me. Do you have a good garden show in your city? If so, please email me a photo so I can live vicariously through you. Or, hey, maybe I’ll send them to next year’s local planning committee. They could use some ideas.
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