I am not sure whether or not to pinch off the old dead flower heads on my rhododendrons. It appears that if I leave the old flowers on, the stems elongate and make new leaves. If I pinch the old flower heads off, will that be better than leaving them on?
Thanks for any advice.
Deadhead old flowers on rhodos? To pinch or not-
I think I answered my own question about dead-heading rhododendrons and azaleas. If they were very large, I wouldn't think of dead-heading them. Too time-consuming! And they would do fine without being dead-headed. So I don't need to dead-head my small ones, unless I want to do so for aesthetic reasons.
Hello, gooberpie. I am jealous that you were getting blooms recently! God, our bloomage in Texas ended a long time ago, seems like years...
As far as your question, I would not deahead because: I am lazy, it can get to be a time consuming process and doing so would remind my pooches that I recently added some Holly-tone and cottonseed meal to the rhodies and hydrangeas.
But if you decide to prune, use your fingers, bend and snap the spent flower part above the new leaves, being careful of any new foliage. It can get sticky so, consider using disposable plastic gloves.
And while you can improve the shape of the bush now, be aware that cutting stems during the summer months can affect next year's bloomage. However, if your plant finshed blooming recently then you may be ok.
Remember to keep an eye on soil moisture during the next few months! I had to tweak my drip irrigation schedule to account for plants that are now bigger than they used to be this time last year.
Wilting and drooping are the first signs and can be safely ignored provided that the plant recovers by the next morning. To verify that the plant has enough water, insert a finger into the surrounding soil to a depth of two inches (roots are usually in the top four inches and that dries up first/fast). If it feels dry then add water. If it feels moist (not wet) then it is ok. If it feels wet, then you either watered recently or need to reduce the amount of water.
Have a great summer,
Luis
The old advise was to always deadhead the spent blooms and that is still good advise because it impoves the appearance of the plant and also remove some chance of disease. Having said that I don't deadhead the large plants because it is too much work and because it doesn't seem to make any difference that I can see as far as the quantity of next years bloom. Aside from the appearance of the plant there is the question of the smaller plant having enough energy to produce both new growth and flowers in the same year. Actually there are very few flowers that are polinated and producing swollen seed pods on small plants and if the ovaries are not fertilized there will be no seeds produced, hence no need for deadheading
This is currently being discussed on the Yahoo "rhodo" mailing list, where a lot of American Rhododendron Society members post, along with a fair number of nursery owners (including Greer from the west coast, and Hank Schannen of Rarefind.
The general consensus is that for many plants it doesn't matter (much) to next-year bloom. Some varieties (like Janet Blair) are very fertile and if not deadheaded will tend to bloom well only every other year. "Ironclads" (a group of older hybrids known for being very hardy on the East Coast) appear to not be affected. Some hybrids are infertile, and so it doesn't matter.
Elepidotes ("small leaf" rhododendrons) and azaleas don't need it (and it would be really tough anyways).