Mimosa Tree Wilt (Fusarium Wilt): Prevention and Management

Overview

Mimosa wilt (Fusarium wilt) is caused by soil-borne fungus Fusarium oxysporum (or F. oxysporum f.sp. perniciosum). While no chemical cure exists once infected, prevention and symptom management strategies can protect trees.

Disease Nature

One of several vascular fungal wilts (including Dutch elm disease). Disrupts water/nutrient transport from roots. Infects roots progressively from small to large to tap roots. Not insect-vectored.

Symptoms

• Leaves droop, yellow, dry, and fall
• Orange-pink fruiting bodies on bark after leaf drop
• Suckers sprout from trunk
• Sapwood turns brown; cut stems show discolored rings; roots have dark rings
• Bark fissures may ooze gummy/rubbery exudate

Prevention Strategies

• No chemical cure post-infection
• Trees in compacted soil near construction are highly susceptible
• Avoid handling infected soil, seedlings, or trees
• Fruiting bodies persist 2 years on dead wood, spreading spores via rain
• Infected seeds transmit disease
• Verify nursery stock is disease-free
• Treat historically infected soil with methyl bromide or biocide before planting
• Sterilize tools between infected and healthy trees

Management of Infected Trees

Remove and burn infected branches. Apply balanced 10-10-10 fertilizer to alleviate symptoms. Water frequently as needed.

Resistant Cultivars

Best control: plant resistant hybrids. 'Charlotte' (light red flowers) and 'Tyron' (deeper red) resist Fusarium wilt. Other resistant options: redbud, honey locust, New Mexico locust.