Horticulturist Conor Guidarelli manages the Arnold Arboretum’s organic materials recycling area and has recently improved the production and quality of the resulting compost.

On June 6 at 6 – 8 at the Arnold Arboretum, 125 Arborway, Conor will discuss the components of compost and the nutrients that can be returned to a site when compost is applied. He will explain the mix of brown to green materials, moisture, and aeration.

Class participants will start in the classroom and then travel to the Arboretum’s materials yard to see compost in various stages of development.

Fee $20 Arboretum member, $30 nonmember.

Register at http://my.arboretum.harvard.edu or call 617-384-5277.