Something Good for the Soil

Soil has been called “the skin of the earth.” That “skin” nourishes much of life here, so let’s take care of it. Which is one reason for cover crops, that is, plants grown not directly for us, but specifically to maintain or improve soil health. Typical cover crops include rye, oats, buckwheat, clovers, and other mostly grains or legumes.
Oat cover cropThe most obvious benefit of a cover crop is the protection it affords the soil from wind and rain, either of which can carry away the most fertile surface layer. Also protection from temperature extremes. Another benefit is that cover crops can suppress weeds. Less obvious is cover crop plants’ ability to grab onto and bring back up to the surface layers nutrients that rain might otherwise wash beyond roots into the groundwater.

Buckwheat cover crop

Buckwheat cover crop at Chanticleer

Some effects are even more subtle. Substances oozing from plant roots feed microbes and also bind soil particles to create small and large pores to create a good balance of air and water in the ground. Cover crops also can increase levels of all-important soil organic matter, which benefits plants and soils nutritionally, physically, and biologically in both known and unknown ways.

But Does My Ground Need It?

Despite the benefits of cover crops, you’ll rarely see them in my vegetable garden. Mostly, that’s because the beds are usually packed full of growing vegetables from very early to very late in the growing season. There’s nowhere to plant a cover crop! The vegetable plants themselves provide the same benefits as would a cover crop, especially since I plant at very close spacing, close enough, usually, to hide bare ground.

Bed of broccoli & endive

Bed of broccoli & endive

Planting cover crops in my garden to increase soil organic matter would be like taking coals to Newcastle. For decades, every year I’ve laid a one-inch blanket of compost over all my vegetable beds. (My book Weedless Gardening describes the whole system of soil care.) The result is soil organic matter levels, last time I tested, at about fifteen percent. No need for cover crops to boost my soil’s organic matter content.

Fifteen percent organic matter is very high. A typical, very good agricultural soil, such as the virgin Midwest prairies, was about five percent organic matter.

Then again, could fifteen precent be too high? Very high levels of organic matter lead to soil tests registering excessive levels of phosphorous and potassium. Traditionally, phosphorus was thought to be so tied up chemically in the soil that it would stay put, but some recent research indicates that water can push some phosphorus into the groundwater if phosphorus levels are high enough. 

Conventional soil tests are for mineral soils, not soils that are very high in organic matter. A soil with around fifteen percent organic matter would better be called a “growing medium” rather that a “soil. Soils naturally this high in organic matter are classified as histosols, commonly called bogs, peats, or moors. Such soils, in contrast to my garden soil, are typically low in plant nutrients.

An obvious way to assess soil management is — duh — to look at the plants and their growth. Everything looks fine.

Problem? Maybe, Maybe Not

Except for a couple of strange goings on in one of my two vegetable gardens. In one bed, planted this year to early turnips and lettuce, now in corn, the corn in half the bed is stunted. (The turnips and lettuce did fine.) Stunted cornIn another bed, tomatoes are doing fine, but are not as vigorous as they should be as compared with another bed of tomatoes in that garden.

Weakly & vigorous tomato bedsMy notes indicate that both beds received their annual blanket of compost, just like all the other beds. Last fall, when the compost was applied, I also sowed cover crops in those beds. Rather than my usual oats cover crop, which winter-kills so integrates well with my no-till system, I sowed crimson clover along with the oats. Why crimson clover? Because it’s pretty when it blooms in spring.
Crimson clover
Crimson clover is allelopathic. Allelopathic plants can biochemically suppress growth or germination of nearby plants; the clover could have adversely affected growth of tomato and corn. Of course, only half the corn bed is stunted but clover germination, if I remember correctly, wasn’t uniform in that corn bed. I’ll file all this in the back of my head for future investigation.

Then again, oats, is also allelopathic, as are rye, sunflower, sorghum, and many other plants, including, most famously, black walnut. Allelopathy is often very specific, an allelopathic plant inhibiting the growth of only some species of plants. Said allelopathic plant might even promote growth of other plant species. Time, usually a couple of weeks, after an allelopathic plant is killed or removed, usually rids the soil of any allelopathic effect.

For completeness, I should mention that the corn and tomato bed problem could be traced to erratic behavior, this year, of my drip irrigation system, which has now been corrected.

I’m going to continue occasionally planting cover crops and will monitor more closely any positive or negative effects — in my garden. As they say in so many arenas: “Your results may differ . . .”


Manure Unnecessary

Manure or not, it’s compost time. I like to make enough compost through summer so that it can get cooking before autumn’s cold weather sets in. Come spring, I give the pile one turn and by the midsummer the black gold is ready to slather onto vegetable beds or beneath choice trees and shrubs.

I haven’t gotten around to getting some manure for awhile so I just went ahead this morning and started building a new pile without manure. It’s true: You do not need manure to make compost. Any pile of organic materials will decompose into compost given enough time.
Compost bins
My piles are a little more deliberate than mere heaps of organic materials. For one thing, everything goes into square bins each about 4′ on a side and built up, along with the materials within, Lincoln-log style from notched 1 x 6 manufactured wood decking. Another nice feature of this system is that the compost is easy to pitchfork out of the pile as sidewalls are removed with the lowering compost.

My main compost ingredient is hay that I scythe from an adjoining field. As this material is layered and watered into the bin it also gets sprinkled regularly with some soil and limestone. Soil adds some bulk to the finished material. The limestone adds alkalinity to offset the naturally increasing acidity of many soils here in the Northeast. Into the pile also goes any and all garden and kitchen refuse whenever available.
Hay for composting
What manure adds to a compost pile is bedding, usually straw or wood shavings, and what comes out of the rear end of the animal. The latter is useful for providing nitrogen to balance out the high carbon content of older plant material in the compost, such as my hay.

But manure isn’t the only possible source of nitrogen. Young, green, lush plants are also high in nitrogen, as are kitchen trimmings, hair, and feathers. Soybean meal, or some other seed meal, is another convenient source.

Compost piles fed mostly kitchen trimmings or young plants benefit from high carbon materials. Otherwise, these piles become too aromatic, not positively.

As I wrote above, “Any pile of organic materials will decompose into compost given enough time.” Nitrogen speeds up decomposition of high carbon compost piles, enough to shoot temperatures in the innards of the pile to 150° or higher. All that heat isn’t absolutely necessary but does kill off most pests, including weed seeds, quicker than slow cooking compost piles.Smelling compost

Plus, it’s fun nurturing my compost pets, the microorganisms that enjoy life within a compost pile.

Novel Use for Microwave

I bought my first (and only) microwave oven a few years ago ($25 on craigslist) and have cooked up many batches of soil in it. You thought I was going to use it to cook food? Nah.

Usually, I don’t cook my potting soils, which I make by mixing equal parts sifted compost, garden soil, peat moss, and perlite, with a little soybean meal for some extra nitrogen. I avoid disease problems, such as damping off of seedlings, with careful watering and good light and air circulation rather than by sterilizing my potting soils.

Peat, perlite, soil, and compost

Peat, perlite, soil, and compost

Recently, however, too many weeds have been sprouting in my potting soil. Because my compost generally gets hot enough to snuff out weed seeds and because peat and perlite are naturally weed-free, these ingredients aren’t causing the problem. Garden soil in the mix is the major source of weeds.

So I cook up batches of garden soil, using the hi setting of the microwave oven for 20 minutes. My goal is to get the temperature up to about 180 degrees F., which does NOT sterilize the soil, but does pasteurize it. Overheating soil leads to release of ammonia and manganese, either of which can be toxic to plants. Sterilizing it also would leave a clean slate on which any microorganism, good or bad, could have a field day. Pasteurizing the soil, rather than sterilizing it, leaves some good guys around to fend off nefarious invaders.

After the soil cools, I add it to the other ingredients, mix everything up thoroughly, and shake and rub it through ½ inch hardware cloth mounted in a frame of two-by-fours. This mix provides a good home for the roots of all my plants, everything from my lettuce seedlings to large potted fig trees.

Blueberry Webinar

Blueberries, as usual, are bearing heavily this year, with over 60 quarts already  in the freezer and almost half that amount in our bellies. After years of growing this native fruit, it has never failed me, despite some seasons of too little rain, some of too much rain, late frost, or other traumas suffered by fruit crops generally.

All of which leads up to my invitation to you to come (virtually) to my upcoming Blueberry Workshop webinar. This webinar will cover everything from choosing plants to planting to the two important keys to success with blueberries, pests, harvest, and preservation. And, of course, there will be opportunity for questions. For more and updated information, keep and eye on, the “workshops” page of my website.
Bunch of blueberries


Soil is Key

    Last week I described my foray into the New Jersey Pine Barrens, culminating in a visit to the USDA research station there to experience many new, interesting, and tasty varieties of blueberry. The soils of the Pine Barrens, as I wrote provide ideal conditions for the rather specific and unique requirements of this fruit.
    That’s not to say that blueberries can’t be grown successfully beyond the Pine Barrens. In fact, they can be grown just about everywhere — if the right varieties are chosen and the soil is amended to suit the plants. The soil here at my farmden, for instance, is very different from that of the Pine Barrens. Mine is a naturally rich silt loam that is slightly acidic; the Pine Barrens are naturally poor sands that are very acidic.
    Both soils are well-drained, which is the first requirement for a blueberry soil. The way to make soils that are less than perfectly drained suitable is to plant the bushes atop mounds or carry water away in ditches or in buried, perforated pipes.
    Next, acidity. The pH for blueberries needs to be between 4 and 5.5, which is very acidic (and is what blueberry relatives such as rhododendrons and mountain laurels also demand). I acidifed my soil with elemental sulfur, a naturally mined mineral, before planting and do so periodically over the years, as needed. Many gardeners pile oak leaves or pine needles on their ground, or dig these materials into soil, to make a soil more acidic — that doesn’t do the trick; sulfur is what’s needed, 3/4 to 2 pounds per hundred square feet for sandy and clay soils, respectively, for each unit of pH change needed.Netted, healthy blueberries
    Blueberries like their roots coursing through soils that are high in organic materials, not rich organic materials such as manure or compost, though. Peat moss is good; I mixed a bucket full of peat with the soil in each planting hole when I planted. To maintain, even increase, levels of organic matter over the years, the ground beneath my bushes, every year, gets blanketed with a 3 inch depth of some weed-free organic material, such as autumn leaves, wood chips, wood shavings, sawdust, pine needles . . . whatever I can get my hands on.
    And finally, blueberries need water, especially when young. That initial dose of peat moss along with yearly, organic mulches, helps the soil hold moisture (in addition to many other benefits).
    Oh, one more thing: Ninety percent of blueberry roots are in the top 6 inches of soil. Hence their need for moisture. Those shallow roots also compete poorly with weeds. My 900 square foot of 16 blueberry plants is, essentially, a “no weed” zone, thanks to the mulch and occasional weeding.

Tastiest Turnips

    Pushing open the gate to exit the blueberry planting, I walk over and pull open the gate to the vegetable garden. There lies a beautiful (to me) row of sweet, succulent turnips. Not just any old turnip, but the variety Hakurei, the best (to me, and many others gardeners and farmers).
    Turnips are an underrated vegetable, perhaps because most that you can buy just don’t taste that good and because most that are grown in home gardens are not the best-flavored. The highest praise I know of for turnips is in the novel Tobacco Road, when Lov Bensey walks seven and a half miles to get a sack of winter turnips for fifty cents, which is half of his daily wage. (Admittedly, he was starving.)
    So here’s at least the second written accolade for the turnip. When a good variety is planted and it is well grown, it is a sweet, flavorful vegetable excellent raw, pickled, or cooked. The variety to grow is Hakurei and the way to grow them is in rich, well-drained soil with a steady supply of moisture, the latter of which mine get automatically via drip irrigation.

Hakurei turnip

Hakurei turnip

    In the past I planted turnips only in late summer for a crop that ripened during the cool weather of autumn. This year I planted an early crop in the greenhouse; that crop was harvested and eaten by mid-June. I had plenty of seed and space in later in spring, so I planted some outdoors then. We’re still harvesting that crop and, despite the hot days, the flavor is excellent. (Cool nights might be helping to maintain flavor.)
    Sometime in the next two weeks, I plan to sow seeds for fall harvest. Last year, that crop, harvested before the weather turned too bitterly cold and the soil froze, went into wooden boxes for cold storage, first just sitting outdoors, then carried into the garage, and, finally, carried down to the cool basement. The last of them, still tasty, were eaten March.