Leaves on my ornamental crabapple tree turn completely yellow, and drop off. Why? No spots beforehand.

Answer

Your crabapple tree may have contracted a disease called Scab (Venturia inaequalis) a dull, olive-green, velvety fungal growth develops on the surface of leaves and petioles in the spring. Leaves yellow and fall prematurely, giving the tree a thin, bare appearance by mid-season. Infected fruit have circular, rough spots on their surface. to help control this problem rake and destroy fallen leaves and fruit. Apply a fungicide as flower buds begin to show color (early spring) and again 3 weeks later. There are resistant cultivars/varieties to this disease (see list below). 

Scab-resistant crabapples: Adams, Baskatong, Brandywine, Callaway, David, Dolgo, Donald Wyman, Malus floribunda, Henry Kohankie, Henningi, Jewelberry, Ormiston Roy, Professor Sprenger, Malus seiboldi var. zum cultivar Calocarpa,

Silver Moon, Sugartyme, Malus tschonoski, Weeping Candy Apple, White Angel, and White Cascade have been observed in many locations to have only slight to moderate scab infections.

Hope this is helpful.

 

For tips on a variety of gardening topics, see our Plant Information Guides.
Courtesy of NYBG Plant Information Service

Topics

  • Last Updated Mar 16, 2021
  • Views 182
  • Answered By Anita Finkle

FAQ Actions

Was this helpful? 0 0

Ask a plant expert

Send us an email or use the question form below.

Submit a question

Before submitting your question, try searching our Plant and Gardening FAQ page and Help Guides. Still need help? Fill out the form below and a plant expert will answer your individual plant and gardening questions. We will respond to questions in the order we receive them.

Your Question
Your Info
Fields marked with * are required.