[Community_garden] Soil Amendments

[Don Boekelheide]

Hi, Susannah ,

(as in "O, Susannah"?)

I'm glad you asked your questions, they are exactly the right focus - the soil. That's where gardening, especially ecologically sound, sustainable and organic gardening, needs to start.

Personally, without knowing more than what you've said, I'd amend your clay soil and not remove it. I agree with others who've suggested that. If I lived up your way, I'd come look. Since you are in Columbus, holy moly! Call the ACGA and Franklin Park, and have somebody from there come over to take a look, or bug your Ohio State Coop Extension horticulture agent! They can also help you arrange that soil test, which is an excellent first step, before you purchase anything major.

As Dr. David Bradshaw of Clemson University says, you can learn to love clay (in the South you have to - I garden in clay soil in North Carolina. If I had to dig out and removemy clay, I'd have to truck Charlotte out of here - the whole place.Where would I put it?.) Clay particles are really tiny, tiny boulders, finely broken down rock. Clay hangs on to nutrients and water better than the other mineral components of soil (bigger rock fragments in the form of sand - like at the beach - and silt). By adding organic matter and handling clay soil properly, you can have wonderful gardens indeed. Look around at the farms (hopefully there are a few left...) and forests around you, growing on native clay soils. Not too bad, right? Why even think of hauling it away?

Gypsum is a good source of calcium that doesn't change the acidity of the soil. If your soil is acidic enough to worry about (about 5.5-6 or less on the pH scale used in the soil test), lime is a better choice for adding calcium and correcting the acidity. Experienced growers often apply lime in the fall since it takes several weeks to make a change, but there are "horticultural" lime products you can apply now (NOT QUICKLIME). Ask Extension or Franklin Park. Gypsum is less particular about time of year of application. But gypsum, while not a bad item, isn't a cure-all for clay, in spite of the silly "clay buster" marketing. 

A better solution, in my experience, is getting some quality yard waste (NOT biosolid) compost (or well composted farm manure if you can find it) and mixing that thoroughly with your clay. If your garden has never been gardened before, and if you can afford it or get a donation, you'll want about 1 cubic yard per 100 ft2 (coverage of about 3-4 inches), based on research findings at NC State. You can save money by organizing your garden into beds or growing areas, and not composting the paths.

Before talking fertilizer, one caution about working clay soil. Do not work clay when it is too wet - you'll get bricks. Again, the place to start is with experienced gardeners who can show you. "Raising" beds (making mounds, or - if you insist and have the money - putting up frames around the beds of masonry or wood) can help with clay drainage and aeration - good soil needs both water and air.

About fertilizer, whether you use an ecological/organic approach or a chemically dependent one, the compost will help your soil use nutrients most efficiently. I'd suggesting learning a bit about what those numbers on the fertilizer bag mean, too! Make it a shared project of your garden group. Different plants have different needs. About an organic approach, good compost generally provides a 'balanced diet' of plant nutrients. You can supplement with traditional materials such as composted manures, or bagged products such as alfalfa meal (rich in nitrogen), bonemeal (good for phosphates), greensand or wood ashes (for potassium), a bit of kelp maybe (for various things). A convenient way for beginning eco/organic growers to ensure the relatively high nutrient levels most veggies prefer is through products such as Espoma Plant-Tone (5-3-3). The Scott's Company, in your neighborhood, has added a line of organic fertilizers (just so you know, they also push
 Round-Up, other chems). Plants need at least 16 nutrients to thrive, not just the "big 3" of the fertilizer bag, and bagged organics generally provide all these.

Using 10-10-10 (don't shoot, Mike!) isn't the end of the world, in my book. It's a "chemical" or "industrial" or "synthetic" fertilizer formulation in the form of salts and acid-treated rock that floods your soil with nutrients. Used in conjunction with composting, it can be cheap, convenient and give reasonably good harvests. More important, it gets people gardening so that Mike (and me, too, actually) can convince them that they can do even better using environmentally friendlier organic techniques. I'm not saying 10-10-10 has no problems (though they pale in comparison to pesticides). On the short list - You can easily burn plants by applying too much, and especially without compost, those soluble fertilizer ions can easily wash right out of your garden and directly into our streams and drinking water. You have to be careful not to get it wet, or it becomes a useless brick. Don't mix it with urea (another familiar cheap nitrogen fertilizer) or you get
 a slimy mess. Don't just think you can put it on and forget it (you can do that with most organic products, since they are 'slow release' by nature, providing your plants with what they need as the season warms up). You'll need to keep applying by sidedressing. Some say that plants grown with high nitrogen chemical fertilizers have more pest problems. Then, there is the environmental costs - But if you are hooked on chemically dependency in the garden, forgive yourself and start gardening. You'll learn. And when you are ready, Mike can suggest a 12-step group for y'all. Intervention, anyone?

Your plant list looks good, though you want to start your cool season crops at different times from your warm season tomatoes and green beans. Ask Franklin Park, and while you are there visit ACGA and give us a report.

Don
http://urbanministrygarden.wordpress.com

PS: On Square Foot Gardening, well, it got a lot of people to start gardening. Like 10-10-10, in a way. Whatever it takes to get folks reconnected to the soil and growing at least some of their own food. Once started, people will grow,  like their veggies and flowers.

From: "Susannah Evans" <susannahevans at hotmail.com>
To: <community_garden at list.communitygarden.org>
Sent: Wednesday, March 26, 2008 1:12 PM
Subject: [Community_garden] Soil Amendments


We have a communal community garden in Columbus, OH - 40' by 80' with a clay

based soil. Our group has had several conversations about amending the soil 
to help break down the clay. Gypsum was suggested and I was wondering if 
there was a good source of gypsum that would be considered organic? We are 
not a completely organic operation, but we try to consider everything we add

to the soil to make the best decision. Also, we are interested in starting 
some of our vegetables within the next month. Would gypsum be ok to apply 
now and till in or should it be applied in the fall.

It was also suggested to add some 10-10-10 fertilizer to boost the soil. We 
are going to have a soil test done soon to see if we have specific pH or 
nutrient deficiencies. Any recommendations on some good organic soil 
amendments that could be added in the spring (or suggestions for fall?). We 
are looking to grow potatoes, tomatoes, green peppers, zucchini, bush beans,

lima beans, peas, lettuce, broccoli and celery.

Thanks,
Susannah Evans
Epworth Veggie Garden
Columbus, OH
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