The leaves of my 5 ft. high oleander have started to wither, dry, and fall off. It appears the bush is slowly dying from the bottom up, around the middle only. What's wrong? Two other oleanders are healthy and green. The dying shrub is situated between the other two healthy oleanders.
Certified GKH Gardening Expert
Oleanders generally are quite disease resistant. The fact that healthy plants are right next too the stressed plant could indicate insects or fungus issues. Remove the dead material and dispose of. Treat with Neem Oil, as this works as both an insecticide and fungicide.
Remember to use protective clothing and gloves when working with Oleanders.
Check watering if the weather has been dry. 2 to 3 inches of hardwood mulch can help with moisture retention.
Here is a link with general care information but it may help pinpoint any other issues.