Stella Otto: The Backyard Fruit Gardener

Today's Tip: Mow vegetation short around the base of fruit trees and bushes to reduce winter habitat for rodents.

Compost No-nos: What Not to Add to Your Pile

The goal of adding com­post to the fruit gar­den is to ulti­mately pro­vide a healthy and whole­some crop for you and your fam­ily to eat and enjoy. Good qual­ity com­post will pro­vide nour­ish­ment to your berry plants, vines, and fruit trees. When grow­ing edi­ble crops it is impor­tant to use prac­tices that will keep that food safe from con­t­a­m­i­na­tion by disease-causing bac­te­ria, viruses, par­a­sites, and other pathogens as well as heavy met­als and pes­ti­cides. Some poten­tial com­post pile addi­tions may be toxic to your garden’s plants in some way. Most of these mate­ri­als will be prop­erly bro­ken down in large-scale com­mer­cial com­post­ing, but since home com­post piles do not always con­sis­tently reach high enough tem­per­a­tures to guar­an­tee break­down, here are some mate­ri­als that should not be added to the home gar­den com­post pile.

May con­tain bac­te­ria, viruses, par­a­sites, pathogens or chem­i­cals harm­ful to humans:
Pet wastes (dirty cat lit­ter, dog or cat feces )
Manure from other meat-eating ani­mals
Grass or other clip­pings  treated with chem­i­cal pes­ti­cides
Ashes from treated or painted wood

May con­tain pathogens that could infect gar­den plants:
Dis­eased or insect-infested plants

May con­tain pathogens or sub­stances toxic to plants or ben­e­fi­cial com­post­ing organ­isms:
Black wal­nut tree leaves or twigs (pro­duce juglone, a sub­stance that is toxic to other plants and stunts growth)
Euca­lyp­tus and ole­an­der leaves and vines
Her­bi­cide and pesticide-treated yard trim­mings
Coal or char­coal ashes (con­tain sul­fur and iron that can be toxic to plants in large amounts)

Can cre­ate odors or draw pests such as flies and rodents:
Dairy prod­ucts (e.g., but­ter, milk, sour cream, yogurt; note — crushed egg shells are not a major prob­lem and add small amounts of desir­able cal­cium)
Fat, lard, cook­ing grease, or oils
Meat or fish bones and scraps

May alter com­post pile pH:
Ashes (are alka­line and in large quan­tity may alter pH. They are also a good source of potas­sium and are fine to sprin­kle on the pile in mod­er­a­tion — up to 2 buck­ets of a ashes for a 3 x 3 x 3 pile)

For other infor­ma­tion see —

Cre­at­ing Com­post
Com­post — Where to Begin
Con­tain­ing Your Com­post
Recipe for a Com­post Pile
Fac­tors that Affect the Com­post­ing Process

Stay tuned for more —
Com­post Conun­drums — Trou­bleshoot­ing your com­post pile
Com­post Myths