I have a rhododendrum bush that is at least 35 years old. i have noticed over the past few years that the blooms are less and that the leaves have gotten progressively smaller. I have the bush on the northewast side of my home, sheltered in a corner away from winds in the winter time. Please tell me what is the lifespan of this type of plant? 40 year? 50 years? more? It has been beautiful over the past 10 years or so, but has gradually diminished in size and blooms. What is the solution?
Though some heirloom Rhododendron have been know to live 100 years, their are many factors that go into the life expectancy of a shrub in the home landscape.
Environment conditions, soil, nutrients, disease and pests can all play a part in the health of a plant.
These links will help refresh you on the care requirements.
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/rhododendron-care.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/issues-with-rhododendrons.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/yellow-rhododendron-leaves.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/pruning-rhododendrons.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/rhododendron-winter-care.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/fertilizing-rhododendrons.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/rhododendron-not-blooming.htm
Is it okay to plant Rhododendron's in an area where 15 year old Arborvitae have grown. They were destroyed by this Winter's snow. I know Rhododendron's like acid soil, but that is all I know. Had 6 Arborvitae trees, want to plant 3 Rhododendron's. Thank you for any help. Sincerely, Elizabeth
You can do a soil test prior to planting to see if you need to amend the soil.
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/rhododendron-care.htm
the stems on my rhodedendrum have gone white on the old wood the new growth is ok what is up with it its in a pot weve had it a few years now
This could be bark scale.
https://www.gardeningknowhow.com/ornamental/shrubs/azalea/common-azalea-problems.htm
HOW DO I PLANT THEM AND WILL THEY GROW IN MISSOURI? HOW FAST DO THEY GROW?
They will grow in all areas of your state. The rate of their growth will depend on a combination of genetics, and the care that they receive. It would be hard to give you an exact growth rate. This article will help: https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/rhododendron-care.htm
Can they be planted over a septic line?
I don't know if I would plant anything large over a septic line, but they do have much less of a tendency to invade pipes, since their roots are more fibrous rather than large and water-seeking. I would have care when planting anything near septic lines, but this would be one of the less invasive plants to put near them.
The blooms are fine but half the main trunk seems to be rotted or eaten away by a bug. Can the hollow be filled with tar or cement? Will send pictures shortly.
This sounds like Rhododendron Stem Borers.
These articles have more information.
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/issues-with-rhododendrons.htm
https://www.gardeningknowhow.com/ornamental/shrubs/azalea/azalea-branches-dying.htm
Pictures per prior e-mail.
This sounds like Rhododendron Stem Borers.
These articles have more information.
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/issues-with-rhododendrons.htm
https://www.gardeningknowhow.com/ornamental/shrubs/azalea/azalea-branches-dying.htm