Spring Plant Diseases and Composting

March 21, 2011 10:16:15 AM PDT
You may be thinking of gardening this first week of spring. And while it's just about that time, there are some spring diseases that require our attention now. You may not see the effects of the diseases until mid summer when it's too late. Doris Taylor from the Morton Arboretum has some helpful tips to prevent these particular diseases. You can also get some hands-on help by attending a class at the Morton Arboretum.

Class Information
April 12- May 3
Soils & Composting Class (H-777)


The Morton Arboretum advises that, there are several landscape diseases that are affecting our trees and plants that we must treat right now, before the leaves come out. After they leaf out, it is too late to guard against these particular diseases. Here are three:

  • Apple Scab: Produces brown spotting on the leaves. Affects crabapples, trees that bear edible apples, and hawthorns.
  • Black knot: creates a black blob, like a tumor, on the branches. This affects cherry and plum trees.
  • Diplodia: kills new growth at the tips of branches. Attacks Austrian and several other pine trees (but not white pines).
  • In each case, the solution is:

    1. Good garden clean-up is essential. Prune off any diseased sections. Gather up any leaves, twigs or branches beneath infected trees, and do NOT compost them, but discard them.
    2. If your tree is small enough, you can apply a fungicide that you can buy at any garden center. Apply three times: first, as the buds open. Next, 2-3 weeks later, and finally when the leaf is fully exposed. However, if you have a large tree, contact a certified arborist for treatments.
    3. Also, sterilize your garden rakes and other implements that may have been infected with disease.

    To create a compost

    1. Combine two parts of "brown" materials (e.g. non-diseased leaves and twigs, etc) with one part of "green" materials (e.g. scraps from the kitchen ? but nothing fatty, such as steak remnants, that would attract animals or create odor.
    2. Four to six months later, expect the mixture to have broken down into rich, organic compost. Apply to trees or shrubs as top-dressing, or when planting, use as a soil amendment.

    For more about composting and keeping plants healthy

    The Morton Arboretum Education Program offers "All About Soils and Composting" (class H-777) starting April 12. Register via Education at www.mortonarb.org or call 630-719-2468.