Reading Soil Test Results

Since I’m gardening in a new yard, I sent a couple of soil samples to the U of M Soil Testing Lab earlier this summer. Most horticulturists recommend a soil test as the first step in planning a garden because it helps you decide what additions, if any, you need to make to the soil.

For years, I did not have soil tests, but instead relied on the mantra: When in doubt, add compost. But I was concerned about the soil in my new garden, so I got the tests done.

A Solid C

The results came back within two weeks and, if my soil were getting a grade, it would be a solid C, maybe a C-.  While not completely surprising, the tests show I have a lot of work to do to build organic matter and soil fertility. I had two different samples tested because I have two distinctly different garden areas in the backyard: one that had been planted with turf and hostas previously and one that had been the site of an old garage. We scraped off some of the garage-area soil and added 2 inches of black dirt, but clearly that was not enough.

The better of my two soil test results is pictured above. This is for the turf/perennial area. It shows a coarse texture—more sandy than clay. The soil has a pH of 7.3, which is not terrible for Minnesota, and an organic matter percentage of 6.7 percent. My previous garden had a similar pH, but organic matter of over 10 percent. To be considered “organic” soil, a garden should have 19 percent or better organic matter. These garden beds will be getting a layer of leaves and compost over the winter and next spring to improve the soil fertility.

As with my previous garden, the phosphorus levels are sky-high. This garden has 51 parts per million of phosphorus, compared to a “very high” level of 25 ppm. My previous garden, however, had over 100 ppm of phosphorus. The potassium level is 76 ppm, a medium score, compared to more than 300 ppm on some soil I was sold for raised beds—which I think is too much.

The two key pieces of information from a soil test are the organic matter percentage and the fertilizer recommendations. The U suggested that any fertilizer I add to these beds have a ratio of 7-0-10—so no phosphorus, but some nitrogen and some potash.

Sandy, Clay or What?

The soil on the site of the former garage was also labeled as coarse by the U, which shocked me considering how difficult it has been to dig in. If the soil is wet, it actually makes a sucking sound when you pull a shovel of dirt out of it. It does have a lot of rocks, so I decided to do the low-tech test to find out if your soil is clay or sand.

This is the test where you put a bunch of soil in a container, shake it up with water and let it settle. Because of the relative weight of the different types of soil (sand, silt and clay), the soil will settle out in layers, with the heaviest layer (sand) on the bottom and the lightest layer (clay) on top. For a better explanation of how this works and how to use a soil chart, check out this fine video.

It took forever for all the sand and silt and clay to settle out of my jar. The photo above was taken 48 hours after I started the test. Most of the videos/pictures I’ve seen show clear water on top and clear layers. My jar has some layers, but there is still a lot of soil floating around in the water.  The soil did not fully settle out until about a week later.  My best guess on composition is it is 50 percent sand, 20 percent silt and 20 percent clay. According to the soil chart (below), this kind of soil is considered loam or clay loam, which should be decent garden soil.

Perhaps the problem isn’t the rocky (inorganic) part of the soil, but its complete lack of organic matter. According to the U, the organic matter level was an abysmal 2.7 percent. This is the reason I’m growing vegetables in raised beds.

But here’s the funny thing about this potentiall atrocious soil–stuff is growing in it! I planted some cosmos and they seem to love it. I put in five plants of ‘Blue Heaven’ little bluestem and they’re happy as can be, as is a ‘Little Henry’ sweet black-eyed Susan plant that I got at a garden writers event earlier this summer, some Russian sage and even allium bulbs. Not everything likes that soil, of course, and three honeyberry plants that I thought might do well there, up and died in just a few weeks. Very sad.

My plan is to buy additional native and prairie perennials for the areas around the raised beds, which will be good for attracting beneficial insects. I’ll also add leaves and compost, but getting this soil to the “organic” level is going to be the work of many years.

Have you had a soil test on your garden? How does your soil measure up?

Repel Rabbits with Plants

Another nice thing about marigolds is they stay blooming well into the fall.
Another nice thing about marigolds is they stay blooming well into the fall.

I’ve had a mess of garden troubles with critters, most of which are of the burrowing variety. But over the past couple of years, my number one garden enemy has been the rabbit. Or rather, rabbits, since I seem to have an endless supply of them eating vegetables, pulling up bean plants and doing lots of unauthorized shrub pruning.

Last year, I put a low fence around my main vegetable area and that certainly slowed them down. But my goal this year is to make peace with the bunnies even more, and a couple of recent garden talks I’ve attended have given me some new ideas. This past weekend, I combined a trip to the Chicago Flower and Garden with a visit to my daughter who lives in the city. Shawna Coronado, noted blogger, author and urban gardener, gave a talk on planting sustainable containers, but also offered a bunch of tips on front yard garden design, composting and growing vegetables in shade.

According to Shawna, you can repel rabbits with plants by growing spicy globe basil combined with marigolds. She particularly recommends ‘Taishon’ marigolds. Both plants have a strong scent and make lists of “rabbit resistant” plants. Will the two together provide extra protection? Generally bunnies don’t care for stinky stuff, so it makes sense that combining two smells might be extra effective.  I’m not sure, but I plan to try the combination this summer.

I already plant parsley for caterpillars/butterflies, so why not a few more plants for the bunnies.
I already plant parsley for caterpillars/butterflies, so why not a few more plants for the bunnies.

Earlier this winter, I reviewed The Wildlife Friendly Vegetable Gardener, a helpful book by Tammi Hartung, who is a big advocate of “decoy plants.” These are plants pests like that you plant somewhere you don’t care about. For bunnies, that means ample parsley planted away from the vegetable garden.

For more ideas on making peace with rabbits, check out the article by Samantha Johnson from the latest issue of Northern Gardener.

Rice County Hort Day: A Gardener’s Education

I don’t remember when I first started going to the Rice County Horticulture Day, but it’s been awhile, and in many ways, attending that annual event was the start of my real education as a gardener. I grew plants long before I started going to the hort day, of course, and I killed a lot of them along the way.  I’ve had a lot of “ah-ha” moments at hort day — moments that prevented more plant killing and increased the joy that I get from gardening.

vendors at mg
Vendors sold jewelry, plants and other things at the Rice County Hort Day.

At last year’s event, Mike Heger’s talk about Heucheras shined a lot of light on why some heucheras flourish in the North and some languish. (It has to do with which species they are bred from.) At an earlier hort day, Mark Seeley gave a frightening talk about climate change that reinforced my sense that gardeners need to protect their little corners of the earth, for everyone’s sake.  One of my favorite presentations of all time was Terry Yockey’s talk on gardening for fragrance — grow plants for all your senses, she said.

This year, promises to be another fantastic day, and if you have not signed up yet, be sure to download the form  and mail it in. Here’s what’s on tap:

The theme is “Garden Magic,” and the event will be held again at Buntrock Commons at St. Olaf College in Northfield. The presentations start at 9 a.m, with Bruce Rohl’s talk about new varieties of peonies (“Not Your Mother’s Peonies”). Bruce runs Aspelund Peony Gardens in Kenyon and is up-to-date on what’s new in one of my favorite old-fashioned plants.

gardeners at mg event
Gardeners picked up great information at the 2012 Rice County Horticulture Day.

The magic continues at 10 a.m. with a presentation Fairy Gardening by Anna Risen of Tonkadale Gardens.  Anna has been designing fairy gardens for outdoor gardens or indoor containers for six years and knows how to bring the fantasy to life.

After lunch, one of the real stars of Minnesota horticulture, David Zlesak, will talk about Success with Roses. David breeds shrub roses and mini-roses for northern climates. I had the pleasure of testing one of his roses in summer 2012. Called Oso Happy® ‘Smoothie’, this rose bloomed and bloomed, practically into November. If you like roses, you won’t want to miss his talk.

The program ends with a talk on What’s New in Gardening, from Mark Armstead, a retailer and grower for Linder’s Garden Center. mark has been watching trends for 25 years and will tell you what’s in, what’s out and what’s new in plants and design.

In addition to the program, there will be coffee, a box lunch (no more tussling with students for lunch!), prize drawings, a silent auction and vendors.

To sign up, download the form here.

 

 

Weeding in November

Saturday was a strangely warm day for November in Minnesota, and I took the opportunity to do some final weeding in my yard and gardens. Our lawn has one section where the grass mysteriously has died over the past year, and it’s very prone to a certain dandelion-like weed. So, that got a good going over as did two shrub and perennial beds where I pulled out thistles, dandelions, grasses and a couple of other unwanted plants.

Why weed in November? The main reason is so that you do not have to weed (as much) in April and May. Several sources I trust say that for every weed you pull in the fall, you won’t have to pull 10 in the spring. That’s a pretty good pay-off!

The weather turned wet (much needed) and cold last night, so I won’t be out in the yard today. What are the final garden chores you are getting done?

Two Things You Did Not Know about Japanese Beetles

Japanese beetle on rose

Japanese beetle on roseI’m one of the fortunate few Minnesota gardeners who — at least so far — does not have a problem with Japanese beetles. The JBs can be extremely frustrating and they have driven two of the most peace-loving ladies I know  to near distraction.

There are lots of rumors about what works and what doesn’t work with the beetles. Hand removing works; traps, probably not. But here are two things you may not know about getting rid of Japanese beetles.

A friend of mine has been squishing the beetles when she pulls them off of her roses. This was good therapy for her. Unfortunately, it turns out the beetles emit a scent when they are crushed and — you guessed it! — the scent attracts more beetles.

Another example: Several experienced gardeners have noted that geraniums appeared to be toxic to Japanese beetles. They wondered if putting the geraniums near other plants the beetles like, such as roses or raspberries, would protect those plants.  It turns out that there is some truth to this. According to the University of Minnesota Extension, a substance in geraniums seems to paralyze beetles — almost as if they were drunk. But, like drunkenness, it’s a temporary condition and eventually they recover.  Also, the beetles don’t learn from their mistakes — they keep coming back to the geraniums. Some research even shows having geraniums nearby brings on more beetles.

The good news is, the beetle season in Minnesota is at least half over.

How do you deal with JBs?

Garden Tours 2011: Raining Ideas

I’ve been on four garden tours so far this summer, and despite rain falling on every tour, the gardens looked lush and beautiful. Tours give me ideas for my own garden as well as for stories for the magazine, plus it’s fun to walk around and see how differently people create spaces in their gardens.

Here are some trends I noticed while walking around in the rain this summer.

Three yards full of exciting plants made for a park-like experience.

Neighborly Gardens.  Northern Gardener ran a feature on two neighbors in Minneapolis who garden, if not exactly together, in collaboration in the  March/April 2011 issue. I saw a couple of examples of side-by-side gardens while touring this year. Certainly the most impressive example were these two hosta gardens in Rochester, which were part of the annual MSHS Garden Tour. The backyards on this street (I think there may have been three yards involved, though only two were technically on the tour) felt like a public park as the yards blended together with similar plants and a shared style. This must present some challenges, in terms of sublimating your personal desires for a shared look, but it’s also a case where one plus one equals about 10.

I believe that is a hydrangea amid the boxwood -- amazing!

Pruning Matters.  Gardens are as much about shape and texture as they are about color, so get out those loppers and prune. Clearly, many of the gardeners on the tours I attended are not afraid to trim a branch or cut an overgrown shrub back — way back. One of the best examples of the power of pruning is the fabulous garden of Ted Bair and Harvey Filister in Minneapolis, which was part of the Tangletown Art and Garden Tour a couple of weeks ago. This yard has Wow! Factor like very few others, with its stone paths and bridges, enormous koi, shape and texture galore. Ted’s the pruner, and he’s not afraid to keep plants small when it suits his design purposes. Many plants can take a firm pruning and look better for it. Prune bravely!

These birds were in at least three gardens I visited, but I liked the placement in this garden best.

Use Art Sparingly, and Well.  There is a fine line between art that is a dramatic focal point and something that is just too much. Many of the gardens on the tours rode that line closely, but didn’t cross it. I really like metal art in a garden because it’s a natural material. I also like art that is hidden for visitors to discover. My favorite example of that was a large (like almost life-size) alligator sculpture that was partially buried in the ground in one garden on the Bright Gardens for Fraser tour in St. Paul. Discovering it was both a surprise and amusing. Gardens do not need to be stuffy.

A stream runs through a hilly garden.

 

 

 

Water Works.  Almost all the gardens I visited had at least a small water feature to bring motion and sound into the garden. Few were as impressive as the one at Erica and Dan Tallman’s garden on the Northfield Garden Tour. The water tumbled down a steep slope in the Tallman’s backyard, complementing the natural setting around it as well as the plants. The Tallmans installed this themselves, which is even more impressive.

My thanks to all the gardeners who opened their spaces to visitors, sharing their hard work and ideas.

Right Plant, Right Place

One of the most repeated mantras in gardening is “right plant, right place.” Like other garden sayings, there is a lot of truth in the advice to choose plants that fit the conditions of a landscape rather than try to adjust the location’s soil, sunlight or micro-climate to fit a desired plant.

Three years ago, I gave up on growing grass in the southeast corner of my lot. We don’t have an irrigation system and don’t want to install one. The corner gets baking sun much of the year. It’s on a slope, so water runs off quickly. Grass likes wet and cool; this spot had hot and dry.

So, out with the grass, and in with a planting bed with prairie plants: grasses, blazing star, Russian sage, perennial salvia, sedum. Now in its third season, I love looking at this colorful bed almost as much as I hated looking at the dry, dead grass that used to be there. And, it’s significantly less work than mowing and watering the area used to be. Each spring, I clean up the area, removing spent plants and stray stems. I usually refresh the mulch and maybe edge it. After that, I just pull weeds, if I see them. In fall, I cut down a few of the perennials and leave the rest for winter interest. That’s the entire maintenance plan.

I’ve only had to replace one plant—a chokeberry bush that didn’t make it through the first winter. Everything else is big, beautiful and soaking up the sun and heat.  Last year, I added these allium because their purple bulbs complement the colors of the ‘Kobold’ blazing star and salvia so nicely.

Right plant, right place. Good advice.