Prayer Plant Yellowing
I have a prayer plant that has recently showed signs of progressive yellowing. Several of my houseplants were recently infested with spider mites, and all houseplants were sprayed every five days for six applications, alternating insecticidal soap and diluted neem oil. The prayer plant in question never showed signs of spider mites, but as it was in the same room as infested plants, was treated as a precaution. Mites have not been seen on the plant following treatment, and the incident may not be related but is provided for context. Recently (after the spider mite treatments had ceased) the plant has begun showing signs of leaf yellowing. This begins in leaf centers as small white spots surrounded by yellow and slightly translucent leaf tissue, as well as edge burn and crumpling along leaf edges. This progresses to whole leaf yellowing, or in some cases orange spots, and leaf death. I have been trimming off affected leaves and parts of leaves, but the symptoms keep appearing. Unaffected leaves seem vigorous, and the plant is still budding new leaves, but at the rate of dieoff, is losing leaves faster than they are growing. I also have several spider plants that are exhibiting similar symptoms, with one leaf at a time turning yellow, then brown and mushy, and falling off. The spider plants are exhibiting much more rapid dieoff than the prayer plant, and are almost completely lost; symptoms in spider and prayer plant started around the same time. I have a ti plant, several pothos, and a zz plant in the same room that have not yet exhibited any similar symptoms. What does this appear to be, and is there anything that can be done? I have attached three photos of prayer plant leaves, one healthy, one with the very first stages of white points with slight chlorosis, and one advanced leaf after being trimmed.
Prayer plants are susceptible to a bacterial disease and we think this might be the cause of the symptoms you are seeing. Sometimes it can be systemic (meaning it will move throughout the whole plant). There is no cure for it, unfortunately. Prune out the symptomatic leaves and keep the foliage dry. That is really all you can do.
Can you send us photos showing the symptoms on your spider plant?
Is there nothing that can be done that can stop the prayer plant infection from becoming systemic? This plant has great emotional significance so am prepared to try anything including cutting back to the ground and trying to regrow, if the infection spreads from the leaves. Is this a possible path forward?
Unfortunately, I recently pruned the large spider plant so the attached image of yellowing leaves (the yellowing proceeds in a mottled pattern) isn't great, but I added an image of a smaller one that has not been pruned, showing green, yellow, and brown leaves.
The only thing we can recommend for the prayer plant would be to prune out symptomatic foliage and keep the leaves dry when you water. Hope for the best. We understand how it is when a plant has sentimental value. Unfortunately, there is not anything we can suggest for a cure.
In spider plants, it is normal for older foliage to gradually turn brown and die back. Cut off those stems when they are withered and become unattractive. Brown tips are an indicator that the plant is either kept too dry or too wet. These should be watered often in the summer, but allow the soil to dry between waterings. The plants can handle drier conditions in the winter when their growth is less active.
Spider plants are sensitive to fluoride in water and too much fertilizer -- both of which can result in tip burn.
Prune out the brown leaves and repot your plants in fresh potting soil. Now is an ideal time of year for transplanting.