Ipomoea arborescens, more commonly referred to as morning glory tree, is a popular addition to many home gardens for its colorful blooms and distinctive leaves. Unfortunately, this tree is highly susceptible to a number of common fungal diseases, especially stem rot during the wetter climates. This dangerous disease can lead to death when left untreated.
Ipomoea arborescens is native to the Sonora region of Mexico; due to its evolutionary propagation abilities and hardiness, the plant has over run much of the area. It can grow up to 30 feet tall and has unusual woody stems with blue to violet flowers that bloom in warm weather. This plant is well known for being banned in the states of Florida and Arizona because of its rapid growth rates.
Morning glory trees that come in contact with the fungi Fusarium oxysporum can easily be infected by stem rot. During times of increased moisture or irrigation, the fungi releases spores that cause the stems of the plant to begin to swell, blocking needed nutrients from reaching other parts of the plant. Symptoms include stunted growth, minimal flowering, yellow foliage and, when left untreated, death.
White rust is brought on by fungi from the Albugo genus. It is an unattractive, but less threatening disease that affects the leaf surfaces of the tree. It appears as waxy, light-colored spots that will progress into powder-white growths and protrude on the under part of the leaf. This disease is nonlethal to trees.
Anthracnose is a common fungal infection that is common in areas where there are frequent heavy rains. Yellow and brown rings form on the younger leaves and spread, forming holes. As the disease progresses, all affected leaves will drop from the tree and spread quickly. This infection can kill weakened trees if left untreated.
The easiest solution to curing fungal disease is to stop the infection before it begins. Avoid over-watering your plants at all costs and plant morning glory trees at least 15 feet apart from each other so that infections don't spread. Many gardeners find it best to clear an infected area of plants, apply fungicide and then wait a full year before replanting. This will give the soil time to kill off any lingering fungi beneath the soil before it has a chance to propagate.
Morning glory trees are well known for their natural hardiness and ability to overcome light infections. Before the infection progresses, gardeners can strengthen the tree by providing it with extra nutrients through fertilization and by pruning off infected leaves and areas before the infection spreads. More often then not, once the infection becomes so severe as to turn stems and organs of the plant black, the tree will die.
Selective fungicides are available on the market to kill the fungus that causes stem rot before it has a chance to infect your plant. These special formulas are designed to leave your morning glory trees unharmed. These sprays are found at most local garden nurseries. Always follow the manufacturer's instructions when applying chemicals to your lawn to avoid further damaging the garden.