Desert willow plants, or Chilopsis linearis, that inhabit your home desert landscape are considered tolerant to a destructive root rot. Unfortunately, tolerance does not equal the immunity that other plants exhibit. Become familiar with the potential dangers of cotton root rot. Through proper maintenance and observation you can keep your home garden desert willows healthy and vigorous.
Healthy desert willows will exhibit greater tolerance and resistance to cotton root rot fungus when compared to stressed or weakened plants. Cultivate desert willows in locations that offer full sun for optimum growth, according to the University of Arizona Cooperative Extension. These plants will also grow successfully in partial shade. Desert willows thrive in a wide variety of soil types but must grow in well-drained soil.
Desert willows can become infected by cotton root rot caused by the fungal pathogen Phymatotrichopsis omnivora, according to the University of Arizona Cooperative Extension. Cotton root rot is a soil-borne fungus that thrives in hot weather and invades the roots of your plants by developing fungal strands that grow toward healthy plants, causing infection by colonizing around root systems.
Cotton root rot fungus problems on desert willows sometimes result in speedy wilt and death of above-ground plant parts like leaves. Once dead, the leaves do not fall from the desert willow. On other occasions, the fungus creates a slow death of your desert willow, particularly in lower temperatures, according to the University of Arizona Cooperative Extension. Roots rot inhibits the plant from absorbing essential water and nutrients, leading to plant death.
Though desert willows are considered tolerant and are less likely to become infected than highly susceptible plants like sycamore, ash and elm trees, planting immune trees means creating a home landscape with no risk of infection. Immune plants include, but are not limited to, agave (Agave species), queen palm (Arecastrum romanzoffianum), trumpet lily (Lilium longiflorum) and California fan palm (Washingtonia filifera), according to the University of Arizona Cooperative Extension.
Selecting immune plants is your best bet in managing desert willow fungus because disease onset is rapid and there are no effective chemical control methods, according to the Oklahoma Cooperative Extension Service. However, for a desert willow showing mild signs of infection, cut the plant back to half of the top growth and maintain consistently moist soil for approximately one month. This natural control may allow your desert willow to recuperate. For severely infected desert willows, remove and destroy the plant.