Composting toxic?

A reader writes in with a question.

My husband and I are renting our first home and I’m excited to start composting as about 70% of our weekly garbage is compostable. It appears as if the family who lived in the house before us set up a wire composting bin directly behind the children’s swingset in the back yard. I was wondering if that was in any way dangerous in terms of toxic fumes, children eating the dirt, etc.

I would not worry.

My four year old helps participate with composting sometimes, and I would not consider compost to be unsafe in any way.

In fact, the EPA has studied using compost as a way to clean up toxic areas. The organic process of materials breaking down into compost also helps get rid of some types of toxins in the soil.

You can always move your bin to a different spot if you are worried about kids getting into it. If you do, I would not have any concern about the former spot where the previous compost bin used to be.

Hope this helps!

Can you compost ashes?

A reader writes in with a question about whether it is safe to compost ashes.

Can ashes from a fireplace be used in a compost pile? Would it be considered “brown” stuff rather than “green” stuff, The only things in the ashes would be newspaper, pine and other dried natural wood; nothing chemically treated.

The sort answer is yes, you can compost wood ashes, in limited quantities.

You don’t want to overwhelm your compost pile with too much of any single ingredient, whether it is ashes or anything else.

Ashes from coal or barbecue briquettes should NOT be composted, because they can contain chemicals that might harm your soil. (Although I must point out that there was a study by Washington State University that determined coal ash up to a certain percentage in compost didn’t harm anything. So maybe I’m just being overly cautious.)

I personally do not like composting wood ashes though, because ashes change the pH of the soil. Ashes are very alkaline.

In fact, if you live in a dry, desert area that already has poor, alkaline soil, you should avoid even wood ash.

Oregon State University Extension Agency has a very thorough article about wood ash and gardening and composting, that is mostly positive about using wood ash with gardening and with composting.

They also mention the pH issue.

For the home gardener, however, wood ash can be a valuable source of lime, potassium and trace elements.

“Since wood ash is derived from plant material, it contains most of the 13 essential nutrients the soil must supply for plant growth,” said Sullivan. “When wood burns, nitrogen and sulfur are lost as gases, and calcium, potassium, magnesium and trace element compounds remain. The carbonates and oxides remaining after wood burning are valuable liming agents, raising pH, thereby helping to neutralize acid soils.”

Where soils are acid and low in potassium, wood ash is beneficial to most garden plants except acid-loving plants such as blueberries, rhododendrons and azaleas. Use wood ash on flower beds, lawns and shrubs.

Hope this is helpful!

Manure Compost: What is it? How to make it? A round up of resources.

Wondering about making compost from manure? Here’s a guide to what you can and can’t do, along with links to some other great resources I’ve found about the subject.

When I refer to manure, I am talking about horse manure, cow manure, and chicken manure.

If you want to know about whether to compost dog and cat poop, please check this page instead.

Horse Manure Compost

Horse manure can be composted, without much difficulty. Whatcom County in Washington State has the clearest and best page about how to compost horse manure, with step by step explanations and instructions. They even go as far as giving you the design for a bin that you can build yourself.

Cow Manure Compost

Managing cow manure issues is more complicated than just composting. It is possible to compost cow manure, but cattle ranchers and dairy farmers will need to follow all of the laws and regulations in their states. This publication features several complex strategies for dealing with cow waste via composting.  Cornell also has a great page with links to many other resources for larger scale cattle issues. If you’re a home composter, it is safe to add cattle manure to your compost pile. Cow manure is high in nitrogen.

Chicken Manure Compost

Seattle Tilth has a terrific, comprehensive guide to composting chicken manure, compiled by Judy Duncan, WSU Cooperative Extension, King County Master Gardener and Cooperative Extension Livestock Advisor. She covers benefits, collection methods, and composting methods, among other things.

Is there anything I missed — either a type of animal, or a good resource? Leave a comment and let me know and I’ll update.