Eggshells fermenting in cider vinegar will be ready March 29 for use as a soil amendment. (Mary Lowther photo)

Eggshells fermenting in cider vinegar will be ready March 29 for use as a soil amendment. (Mary Lowther photo)

Mary Lowther column: Making use of apple cores and eggshells in the garden

When I added the cider vinegar to the shells, it bubbled and fizzed

By Mary Lowther

One of the things David and I share in common is a love of the printed word. When we met he had three rooms full of books, and I knew he had serious intentions when he got rid of a few thousand of them to make room for me. For the last quarter century I have been dealing with a large pile of incoming volumes he has brought home and not yet had time to open, but two years of enforced isolation and long winters appear to have changed all this because, after a lifetime of threatening to do so, David seems to have caught up on his reading.

I reached this startling conclusion when he called my attention to a book review in a copy of Small Farm Canada magazine I left out. It was David who asked me if I would be interested in The Regenerative Grower’s Guide to Garden Amendments, by Nigel Palmer. I now know how Robinson Crusoe felt when he saw that footprint in the sand.

My regular readers (both of you) will be aware that I spend a fair amount of ink writing about the need to ensure that the soil we plant in has the nutrients required to produce the healthiest crop. Author Nigel Palmer has taken this to the next step by discussing how to produce those often expensive and hard to find nutrients for ourselves. In his book he details the results of his search for cheaper, local sources in easy to use ways. Eggshells, he says, are an excellent source of calcium and rich in other minerals plants need. He includes his process, and since I have a steady supply of egg shells and apple cores and peels, I decided to test his methods.

First I made apple cider vinegar by soaking my apple leavings in water for two months at room temperature, then straining the fluid out and leaving it to ferment for another two months. In the meantime I collected egg shells, careful to clean out all the albumen before leaving the shells to dry in the sun.

When I added the cider vinegar to the shells, it bubbled and fizzed just like the author said it would! This fermented concoction should be ready in two weeks, to be strained off, bottled and used. Palmer recommends a dilution of one tablespoon to four gallons of water. If I add it to my compost tea and use it as a soil drench or foliar spray, my litre of extraction should last at least as long as our growing season. Evidently the eggshells can be used two or three more times before adding the spent shells to the compost heap, but I’m going to use meat bones for my next extraction because his studies show that they provide phosphorus as well as calcium; his vinegar extraction from cow bones showed an impressive 1,691 parts per million for calcium and 509 parts per million for phosphorus, as well as several other minerals. I obviously need to make more apple cider vinegar.

Cider vinegar extraction from eggshells, oyster shells and bones is only one method Palmer uses to augment his garden. He also makes plant juices and picks up buckets of rock dust from local quarries. He says that most quarries have an analysis of the minerals in their rock dust so I’ve contacted some of the ones here on the island to see if any are useful to me, but before I get the dusts, I’ll have my soil analyzed to see what minerals it already contains. Once I know that, I can fill in gaps that I hope local rock dusts can provide; if not, I’ll have to keep buying them because I’m learning that without a full complement of minerals, plants don’t thrive as they should and won’t provide me with nutrient dense food.

I found it fascinating when Palmer explained that his inspiration for the vinegar extraction method was a science experiment remembered from elementary school. It made me wonder if the teacher expected any of the students to actually listen to a word she was saying, and how gratified she would be to learn one had. Teaching seems a lot like gardening. You cast your seeds, hoping some take root. Fortunately for gardeners, rain and sunshine are more reliable than adequate government funding.

Please contact with questions and suggestions since I need all the help I can get.