Though exotic, vivid bird of paradise plants are generally known for their disease-free life in your home garden, they are not totally immune to illness. A particular bacterial wilt disease can wreak havoc on typically healthy plants. If you provide consistent care and get to know what to look for, as well as exercise some effective controls, you'll keep your colorful garden healthy.
Vigorous plants are less likely to suffer from bacterial infection and more likely to overcome disease. Grow your bird of paradise plants (Strelitzia reginae) in locations that offer full sun exposure for healthy development of vibrant flowers. Ideal climate includes 60 percent humidity with daytime temperatures of 65 to 70 degrees Fahrenheit and nighttime temperatures of 50 to 55, according to the Clemson University Extension. Provide moist, well-drained soil to avoid waterlogged roots.
Though seldom a problem, the disease Southern bacterial wilt, caused by the bacterium Pseudomonas solanacearum, affects bird of paradise plants by invading the roots. The bacterium is soil-borne and may remain alive in soil for up to six years, according to the University of Illinois Extension IPM. Southern bacterial wilt pathogens are also spread through infected water, fallen plant parts and contaminated equipment.
Once infection occurs, the onset of symptoms is immediate, particularly in warmer temperatures. Look for leaf wilt and fading of green-hued plant parts. As the disease progresses, leaves die and the base of the stem darkens until it becomes black. Symptoms ascend the plant, beginning near the soil line, unlike the symptom displays of other bacterial problems. Damage includes the death of roots, bloom failure and plant death, according to the University of Illinois Extension IPM.
If you choose to replant because your bird of paradise dies or if you are adding other plants to your home garden, avoid the addition of susceptible plants as an attempt to control the spread of disease and to avoid a damaged garden. Other susceptible host plants include, but are not limited to, gerberas, sunflowers, salvias, marigolds and zinnias, according to the University of Illinois Extension IPM.
To control disease of your bird of paradise plants, remove and destroy infected plant parts. Avoid overhead irrigation as standing water creates an ideal environment for the collection of bacteria that may spread to other plants. Maintain uncontaminated conditions by sanitizing pruning tools between each cut and from plant to plant; keep your hands and other equipment clean to prevent spreading the disease.