Cat's Garden: Garden Soil

Augmentation & Fertilization

David B. just sent me some good info from his gardening experiments:

  1. Since plant roots go where the fertility is, I've been experimenting with deep soil fertilization:  Dig a hole about 3 feet deep and 2 or 3 feet wide; fill them with mixture of topsoil and compost. A person can also dig a hole and dump organic matter into it, adding topsoil periodically. Earthworms do the rest. Eventually one has an extremely fertile piece of ground in which to plant a fruit tree, tomato plant, rose bush, or vining plant. One could even plant a circle of corn - 6 or 8 plants or a few sunflowers. In that kind of fertility sunflowers get huge and vining plants become incredibly productive.

  2. This spring, I dug four holes on my neighbor's property next to my driveway, ringed them with rocks to make hills, filled them to the brim with the compost you saw in the Daily Interlake article, and planted squash, watermelon, cantaloupe, and cucumbers. I got the seeds planted June 20 and still managed to harvest two cantaloupe. The watermelons didn't make it. Next year I'll build the rings a little higher, plant earlier, and tent each hill with a plastic ti pi. I anticipate harvesting cantaloupe from mid August onward.

  3. You can plant lettuce and spinach in July, August, and September. September plantings will live through the winter and finish their growth cycle the next spring so you get an early crop to start out the season.


  1. Chicken manure is one of the best manures to use in a garden.  You can buy dry pellets, bagged fresh manure, or bagged composted manure. I bought the latter, by Whitney Farms; use 1 part manure to 3 parts soil (2” manure over 6” soil, total depth 9” spade (see Alaska Mill & Feed).

  2. One 1-cu ft bag of chicken manure will cover 6 cubic feet if spread 2” thick, or 1.5 feet of my 4-ft wide garden. My garlic-spinach-lettuce area is 3’ x 4’ so will require 2 bags. (Total 6 - 8 bags for the entire garden).

  3. Apply to dampened soil 1 week before planting, throughly mixing into the soil at least 1-spade depth.

  4. Also add chicken manure to a compost pile to heat it up.

Augmenting with boron (borax)

Much of our soil is boron deficient due to the use of synthetic fertilizers and other problems. Sandy soil is especially prone to boron deficiency. And this deficiency can be passed on to you, when you eat boron-deficient foods. For more about the health benefits of boron, see my article: Health Benefits of Boron.

You can augment your garden soil with borax, so that your plants (and ultimately you) will be more rich in boron content. However, your plants will suffer if you use too much (borax is also known as a weed-killer, and any plant can be a weed).

Here are some tips I’ve found on the web.

  1. E-How says, “Borax contains boron, an essential micronutrient that helps plants transport sugar. The trick it using boron in the garden is getting the amount just right. It acts both as an herbicide and a plant food, depending on the amount used and the type of plant.”

  2. Another E-How article: Gardening with Borax:  To augment the soil for cabbage-family pants: Use 1 part borax dissolved in 10 parts water (I think this is too strong. See the next item from E-How for a better ratio). A stronger solution can be used to rid your garden of ants, weeds and moss. See the article for details.

  3. Another E-How article: Borax & Vegetable Gardens: Boron builds up in the soil and will last for 3 years. Be careful not to overdose your soil, as too much can kill your plants.

  4. Symptoms of boron deficiency vary widely among plants. They include dark purple or black foliage, dead growth tips and dark fruit and roots with dead spots. Root crops often have black spots or black centers. Cauliflower may have brown areas; celery and broccoli develop hollow, cracked stems. To treat, mix 1 Tbsp borax in 3 gallons of water - this is far more dilute than the previous E-How article.

  5. For killing weeds, it is best to spray the solution directly on the foliage rather than mixing into the soil, since boron will build up over time and could become toxic to your veggies and flowers. See E-How: Can Borax Kill your Garden? for more.

  6. Love-to-know-Organic says, “Broccoli and other cabbage family plants display boron deficiency with hollow stalks, and beets with black spots. Strawberries may also develop a boron deficiency. If you suspect that your plants may have a boron deficiency, conduct a soil test to be sure. directions: Add 2.5 oz of borax into 5 gallons of water and a few drops of dish soap. Spray the solution evenly on plant foliage. Do not concentrate the solution in one area.”

  7. SF Chronicle’s HomeGuide says, “While borax in large doses kills unwanted plants, in small doses it can be a soil booster -- especially in sandy soils that may be soil deficient. A large vegetable garden of 1,0000 square feet can safely benefit from 6 - 7 tablespoons of borax mixed in at tilling, either directly, or diluted in water. Fruit trees, such as apples, benefit from the effects of borax which not only fertilizes but can assist in fighting off rot and fruit-pitting.”

pH, by Crop

I was curious about using wood ash in compost or garden soil; in my research for a post on the ESP website, I learned that not all plants can benefit from the addition of wood ash because it raises the pH. For this reason, it should not be added to compost, but rather used only on soil where it is needed. One crop that definitely will NOT benefit from the addition of ash is potatoes, because ash encourages the growth of scab..

So then, which garden plants can benefit from a higher pH? Several websites have good info including:

  1. Is wood ash good for garden soil?

  2. 2.Garden Wise: Using Wood Ash in the Garden

  3. 3.Hume Seeds: How to use wood ash in the garden


Optimum Soil pH Ranges for Vegetables & Herbs (alphabetic order) from

A few items not listed above include (from unless noted otherwise):

  1. Chard, pH 6.2 - 6.8  (from

  2. Oregano, pH 6.0 - 8.0, like its closely related cousin, marjoram.

  3. Tarragon, pH 6.5 - 7.5

  4. Winter Squash (similar to pumpkin above), pH 5.5 - 7.5 (from Ohio State U)

Altering pH

In an Organic garden, sulfur is added to lower the pH (more acidic); lime or ash are added to raise the pH (more alkaline).


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  1. Main Menu (my home page)

  2. Cats Garden Menu

  1. Augmentation & Fertilization

  2. Manure

  3. pH, by Crop

  4. Altering pH