Volume 14, Issue 2 ~ January 12 - 18, 2006

The Bay Gardener

By Dr. Frank Gouin

Wood Ashes Belong in the Garden, Not the Garbage

Sweeten your soil and avoid an unwanted second fire

If you are burning wood, pellets or corn, you will be generating ash. The wrong thing to do is to place the ashes in a paper bag and to leave the bag outside where it will become wet. The ashes produced by combustion are rich in calcium that has been converted to calcium oxide. When concentrated calcium oxide combines with water, it generates heat, which has been known to cause paper to burn.

The best and safest place to dispose of ashes is in your garden. Ashes from the burning of wood or seeds are rich not only in calcium but also in potassium, with some phosphorus and numerous trace elements. All are essential for making plants grow. Ashes can be used as a liming agent to raise the pH of soils, sweetening them. A 12-quart pail full of wood ashes spread over 100 square feet will raise the pH by approximately one-half unit. This means that if your soil has a pH of 5.0 the addition of 12 quarts of wood ash to 100 square feet of soil will raise the pH to 5.5.

Since nearly all of our soils here in southern Maryland are acid, it is important that we periodically lime our soil in order to maintain a proper pH. I burn approximately 1.5 cords of wood each year and spread the ashes in my garden, which is 60 by 90 feet. As a result, I have not had to add limestone to my garden in 12 years. Last year’s soil test indicated a pH of 6.8 with high levels of potash, medium levels of phosphate and an abundant supply of trace elements. Since wood ashes do not contain magnesium, I did have to apply magnesium fertilizer and, of course, nitrogen.

Never add ashes to your compost pile. The microorganisms at work in composting prefer a mildly acid environment. Adding ashes to your compost pile will raise the pH above the desired level — unless you are trying to compost pine needles. Pine needles are very acid and require the addition of lime or small amounts of ashes to promote composting.

Will old narcissus bulbs bloom again?

Q I’ve replanted the paperwhite narcissus bulbs I forced last year, but instead of early spring flowers all I’m getting are long green stems. Should I have followed the directions, which said to throw the bulbs away after the first year’s bloom?

—Carrie Steele, Bay Weekly staff writer

A Paperwhite narcissus can be replanted for many years — as long as the flower bulb is not killed by cold. After the foliage dies, they need a dry, dormant period before they’ll bloom again, but not a cold dormant period. If you put your bulbs outside after they bloomed, that’s the problem.

Ask Dr. Gouin your questions at [email protected]. All questions will appear in Bay Weekly. Please include your name and address.

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