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.Read More»
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.Read More»
Spring is just around the corner, which means ordering seeds and plants tops most gardeners to-do lists at the moment. I grow heirlooms and hybrids, so the pile of catalogs on our coffee table is out of control. Normally, I find ordering seeds a relaxing experience, but this year I’ve been mulling over a couple of issues that have made placing orders more stressful.
The biggest one concerns GMOs (Genetically Modified Organisms). There’s been a lot of buzz lately about the need to avoid buying GMO seeds for our gardens, and you’ve probably seen at least some of the various lists going around touting ”safe” seeds. Many people, including me, don’t want to buy seed that has been genetically modified. So I was happy to find out from my friend Jeff Gillman, a hort professor at the University of Minnesota, that GMO seed is not yet available to home gardeners.
Farmers have long been able to buy GMO seed, particularly for corn and soybeans, alfalfa and sugar beets. But, at least for now, that seed isn’t available to the general public so we can’t unwittingly buy them off the shelf or online—unless we pretend to be farmers for some weird reason. So where does the confusion come in? Well, maybe because you can mistakenly buy seeds from Voldemort, I mean Monsanto. And where there is Monsanto, we assume rightly or wrongly, there are GMOs.
How could you mistakenly buy from Monsanto? Well, as you may already know, the company has purchased many independent seed companies in the U.S. and abroad over the years. The biggest coup was in 2005 when Monsanto acquired Seminis, Inc., estimated to control more than 40 percent of the U.S. vegetable seed market and around 20 percent of the world market.Read More»
Do your echinacea (coneflowers) look like mutant, green monsters from an alien universe? Mine do. And that’s because a disease called aster yellows is running rampant in Minnesota this year. The disease is caused by a phytoplasma, a microscopic bacteria-like organism that makes its home in the vascular system of plants.
Not all plants can become infected with aster yellows, but many annuals, perennials, vegetables and weeds are affected by it, including asters, carrots, chrysanthemums, coreopsis, cosmos, daisies, dandelion, marigolds, onions, petunias, potatoes, thistle and tomatoes. Aster yellows isn’t a new disease. It’s just worse this year than it normally is for reasons experts are still pondering. Hot weather seems to have something to do with it.
Aster leafhoppers are the reason why the disease travels through gardens so quickly. They transmit the disease from plant to plant when they feed on infected plants and suck up sap that contains the phytoplasma. After a short incubation period in their tiny bug bodies (the leafhoppers are not harmed), the microorganisms multiply and the insects spread the disease further as they feed.
The symptoms of aster yellows vary from plant to plant. But most of the time you’ll notice that infected plants look stunted and distorted in weird ways. Foliage can be yellow and flowers often look yellow or a spooky shade of green. Seeds and fruit don’t develop. You might also see spindly stems and flower stalks. It’s not a pretty sight.
The biggest bummer, though, is that once a plant has aster yellows it can’t be cured. You’ve got to rip the whole plant out and throw it away. I know, I know. I don’t do that either. I just cut off the infected part of my coneflowers and let the rest of the plant that looks good stay. But that is a bad idea. Yes, I get to enjoy the relatively normal-looking parts of my alien, mutant coneflowers. But by allowing those plants to stay in the garden, I’m ensuring that aster leafhoppers will continue to spread the disease to other susceptible plants in my yard and my neighbors’ yards.
It’s really the same tough reality crew members on spaceships in sci-fi films often face. You remember the plot. They all know that their friend was infected by some horrible monster creature thing down on the planet they just visited without wearing proper protective gear (what’s up with that?). And they all know it’s only a matter of time before a baby monster creature thing bursts out of their friend’s chest and tries to infect them all. But, hey, for the moment the friend seems mostly fine, so why not let the poor sot live, right? We know how that story ends.
So let’s all vow to rip out plants infected with aster yellows—at least by the end of the season when we cut down plants for fall. It’s fine to throw these infected plants in the compost because the phytoplasma dies when the plant dies. Not all plant diseases work that way. Unfortunately, this harsh step won’t guarantee that aster yellows won’t come back again next year because infected leafhoppers are likely to still be around or you could inadvertently bring an infected plant home from the garden center. I think I’m finally going to give up on coneflowers all together. I like them, but I’m tired of knowing there’s a mutant, green monster lurking behind those pretty purple flowers.
Note: This post ran this week as my Everyday Gardener column in Minneapolis’ Southwest Journal.
Minnesota is known for extreme weather. We think nothing of a few 90-degree days followed by a 50-degree week, the drastic temperature changes producing everything from thunderstorms and hail to eerie green skies teaming with funnel clouds. “Meh,” we yawn. “We have basements.”
This year, though, things are really weird. After a winter that wasn’t, spring came early and between the already excessive rain, heat and humidity our gardens have gone wild.
Some of you might remember a column I wrote a few weeks ago about how we made a raised bed out of a livestock trough. Well, the tomato in that trough is huge now and the chard, kale and peppers are well on their way too.
I’ve never grown so many edibles in pots and raised beds, so every day when I go outside to check on them I’ll thrilled to find that everybody is still alive, even thriving—this despite the ravenous squirrels, rabbits, chipmunks and racoons that call our yard home. (We even saw a possum scuttle under our neighbor’s porch once.)
Here are a few pictures I took of the garden yesterday that I thought I would share. If you notice I’m doing something that you think could be a problem, please tell me! Like I said, I’ve never tried growing some of these things and I’ve certainly never tried putting so many edibles together in containers to maximize space.
Potatoes are new to the garden this year. I’m growing them in a fabric bag from Gardener’s Supply that I’m product testing. You fill the bag with soil as the potatoes grow. So far so good.
People often ask me what they can use to make raised beds and these galvanized troughs are the first thing that come to mind. Relatively inexpensive ($89 for a 4′ x 2′ x 2′ tank) and durable, livestock tanks make it possible for gardeners to create raised beds quickly and easily.
We got ours because we’d like to grow vegetables and herbs free from pee—and worse—and our lie that the backyard kitchen garden has an electrified fence around it no longer fools our dog, Lily. Troughs are also a great solution if you’ve got poor soil and you don’t want to have to amend a large area. Wall-to-wall cement outside your apartment? No problem. Plop a galvanized tank down, drill some holes in the bottom and you’ve got yourself a garden.Read More»
This past weekend I did a couple of presentations at the Minnesota Landscape Arboretum that had nothing to do with growing edible plants. And yet, on the breaks in between the talks, the number one thing everyone asked me about was how to grow something at home that they could eat.
Washing my hands in the bathroom, snarfing a quick sandwich next to my car in the parking lot, struggling to get my PowerPoint to work — it didn’t matter where I was or what I was doing, people really wanted to know things about growing food.
I honestly lost count of how many times I was asked whether it was safe to use water from rain barrels on edibles. Time after time, though, I told people the same thing: I wouldn’t do it. Though there are few studies on what’s in the water inside rain barrels, research has shown that it often contains chemicals from roof runoff and air pollution, as well as bird poo, mold, fungi and other stuff that sounds unappetizing at the very least.Read More»
One of the things I love most about summer is having an herb garden right outside my back door. Oregano, basil, dill, tarragon, sage, lavender, parsley and several kinds of thyme are right there ready to snip and toss into soup, salad or whatever we’re making, anytime. Sadly, having fresh herbs at the ready is just a six-month pleasure here in the Arctic, so in recent years I’ve been trying to grow herbs indoors once the weather starts to turn cold. I say “trying” because, honestly, it has been a bit trying, literally. But I’ve worked out some kinks and I’d like to share what I’ve learned with you now.
By far, the biggest challenge when growing herbs indoors is lighting. I’ve read, and people have told me, that it’s possible to grow some herbs fairly well in a sunny window. I say those people don’t live in Minnesota in the winter — or maybe they try to see the good in spindly plants where I’m more in the “off with their spider-mite-infested heads” camp. There is one exception: chives. Chives do last a long time when grown in a sunny spot, and you can snip off what you need for months as long as you leave at least 2 inches of growth on the plant.Read More»
If you haven’t yet heard of basil downy mildew, you will. New to U.S. gardens in 2007, the disease has already been confirmed in more than a dozen states. The first sign of trouble is grayish spores on the underside of leaves. But these usually go unnoticed until the disease progresses and yellow splotches appear on the tops of leaves.Read More»
I saw my first butterfly of the season the other day. I am but a rookie lepidopterist, so I don’t know what kind it was. All I saw was a streak of black, not nearly enough to be of help when looking it up in my field guide. As it swooped over my brown, sleeping garden, I worried about what in the world it would find to eat in these early days of spring. What was it doing here so soon?
The only thing I’m sure of is that it wasn’t one of our Eastern black swallowtails. It’s wings didn’t have the right yellow spots and blue patches. I say “our” swallowtails because for the last two summers my husband, Mike, and I have tried raising swallowtails on our front porch. We got the idea, or I should say I got the idea and my ever-patient husband went along with it, from a man named Jim.Read More»