Since "bovine spongiform encephalopathy" (BSE), also known as mad cow disease, surfaced in the U.S.A., I've been getting calls from folks who want to know if bone meal and blood meal are safe to use in the garden.

Mad Cow Disease And

Creutzfeldt-Jacob Disease

Fatal to cattle, BSE has infected more than 183,000 cattle in Great Britain since 1984.

On Dec. 23, 2003, a case of BSE was discovered in the U.S. The stricken cow was born in Canada and imported to the U.S. in 2001.

When humans ingest certain cuts of meat from cattle containing BSE, they contract a variant, fatal form of BSE called "Creutzfeldt-Jacob disease" (vCJD). So far, 153 cases of vCJD have occurred worldwide.

The beef parts believed to cause vCJD include brain, spinal cord and small intestine. These parts, however, don't typically enter our food chain directly. Instead, they go to rendering facilities that reduce them into compounds that are used to make cooking fat and animal feed, for example, as well as fertilizers such as bone meal and blood meal.

Even so, authorities believe that three gardeners may have contracted vCJD in Great Britain from feeding BSE-contaminated bone meal to roses.

Inhaling bone-meal dust, allegedly, caused the infection.

Are Bone Meal And Blood Meal

Safe, Soil Supplements?

Why were English gardeners feeding bone meal to their roses anyway?

Plants require three essential elements to thrive: nitrogen, phosphorus and potassium (N,P,K).

Bone meal that's rendered from cattle (2,12,0) is an excellent and inexpensive source of phosphorus.

Blood meal (14,1,1), rendered from cattle too, is a good organic source of nitrogen.

Meanwhile, the outbreak of vCJD in Great Britain corresponded to a change from using both heat and solvents during the rendering process to just using heat.

We now know that the special solvents used during the rendering process destroy the agent that causes vCJD in humans.

But rendering firms in the U.S.A. are still required - and always have been required - to use heat and solvents to render cattle parts.

Presumably then, bone meal and blood meal - produced in the U.S.A. - are safe to use in the garden.

Taking Extra Precautions

I'm not afraid of using bone meal and blood meal in my own garden. Still, if you're concerned about using bone meal and blood meal in your garden, you could use other, organic supplements. Plenty of products exist. For instance, I use cottonseed meal (6,2,1) on a regular basis as a soil supplement.

Of course, switching to synthetic, soil supplements - such as "triple super phosphate" (0,46,0) and "diammonium phosphate" (18,46,0) - will also satisfy the nitrogen and phosphorus needs of your plants. But these aren't organic products.

By the way, my wife, Judy, tells me that meat loaf is on tonight's menu.

This Week In The Garden

Jeanne Bowman, a reader of this column, has noticed that bag worms (Thyridopteryx ephemeraeformis) are attacking spruces in Shrewsbury, Pa. If bag worms are in Shrewsbury, they're elsewhere too.

Except for removing the bags (small cocoons) by hand, nothing can be done until May.

When May arrives, I'll write more about how to deal with this serious pest.

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