Carrot: Leaf spot
categories: Carrot Carrot Diseases Vegetables
last review date: 2025-10-30 02:26
Photo by: R.S. Byther
Biology
Leaf spot of carrot is also known as early blight. It is a fungal disease. The disease produces leaf and stem spots, primarily attacking young leaves. Initially the spots are small, with yellow halos or margins. Older lesions may become tan or light gray as the fungus produces spores on the infected tissues. Severe infections may result in death of leaves.
Disease spores can be spread by wind. The fungus primarily overwinters in diseased plant material. Leaf spot may be confused with leaf blight, which generally attacks older foliage.
Management Options
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
Non-chemical Management
Select non-chemical management options as your first choice!
- Rotate crops. Allow two or three years between carrot crops in a given location.
- Plant in well-drained soils.
- Schedule watering so that carrots are dry by night.
- Remove plant debris from the garden. Destroy or discard (do not compost) diseased materials.
Chemical Management
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.
- Apply when plants are 6 inches tall or when disease threatens.
- Repeat at weekly intervals if necessary.
Approved Pesticides
Examples of pesticides that are legal for home use in Washington State are listed below.
The list may not include all products registered for this use.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.