Q.My Oleanders Look Very Sick
They have been there for over 20 years. I would like to know if I should cut them down completely (a landscaper said to do that) or can they be trimmed and treated and brought back to health. They are watered 2x/week with an on-ground system.
Certified GKH Gardening Expert
Rejuvenation pruning may be a good idea. If you have an insect problem, that would take care of it. First you might try watering more deeply when you water. If they are just getting shallow waterings, they may need more. They should be watered deeply once or twice a week, according to the articles below. Under or overwatering can cause yellow, dropping leaves. But they do need pruning. I'm including a link to an article on pruning, and it does say, you can do it over a few years, rather than all at once, depending on the health of your shrubs.
Probably. I prefer to “clean” them up myself before taking those drastic steps. I remove dead wood first to see what is left so I get a better view of the existing plant structure. A bad freeze here in Texas in Feb 2021 did for free what your landscaper suggested.