How to decipher compost testing results

Compost made by local municipalities can be a great resource — if you know how to decipher the paperwork that comes with it. Mike McGrath, host of You Bet Your Garden, reveals what all those numbers mean to your plants. Plus your fabulous phone calls.

Question of the Week:

I have been going to the recycling center in Fairmount Park and bringing home buckets of their free compost. But as I listen to you more carefully I’m wondering if the compost is full of pesticides. An analysis from the soil lab at Penn State is posted at their website, but I don’t know how to make sense of it. Can you help? I know I should just make my own. And I’m working on getting a worm bin set up!

— Lucinda in the Germantown section of Philadelphia

Find out if it’s good compost or bad compost »

• Photo by Flickr user Scot Nelson

Highlights from show for April 23, 2016:

Manure for compost

Suzie in Southern, California has a miniature pony and horse. She collects their manure and places it in piles. In order to do that, she scoops it at the expense of her bad back. Because of her back she wants to know if there is a manure in particular, that is already composted to save her less work. Mike tells her horse manure is just rich in nitrogen and will inhibit fruiting, but sheep manure would be her best fit, because she wouldn’t even have to compost it. He says after she collects the sheep manure, she only would have to place it under the fruit trees and it’ll do the rest. Also horse manure contains too much nutrients that’ll just over-fertilize the crops; therefore sheep manure would work best.

Troublesome voles

Mark in Appleton, Wisconsin has a vole problem and wants to know how to get rid of them. Mike suggests he get rid of the wood mulch he has, because that is where the voles are living and is no good for his landscape. After he gets rid of the mulch, Mike tells him to spray it with a concentrated castor oil product heavily in the Spring to introduce a bad smell in the ground that’ll make voles move away. If that doesn’t seem to work; Mark then could set up a trap in the soil to catch them.

Troubled tree

Mike in Washington, New Jersey has 2 acres of trees on his property. He suspects the bark and limbs on the trees are beginning to fall apart; believing termites are the problem. Mike tells him, it’s probably not termites attacking, because they usually eat dead wood. He says the limbs detaching is normal, but for people passing by under it is dangerous. He suggests calling a certified arborist for a pruning job over the winter to help the trees recover.