Nova Zembla rhododendron

[mangcorn]

I wonder if anybody has success with growing Nova Zembla rhododendrons. I bought 2 of these beautiful rhododendrons 6 years ago in New York, and they almost never grew or bloomed properly, even after I transplanted them to a new place (in Connecticut). They both just looked miserable, with very few leaves on top, and almost no flowers. There were no signs of pests or diseases. This year I bought another one in the spring which looked gorgeous and was blooming profusely. It was growing nicely and looking good all summer, but in September I noticed that the leaves turned pale and dull, drooped and curled a little bit. Again, no signs of pests or diseases (and I spray it with Neem oil from time to time). The soil has good drainage, never soggy (just moist), and I checked the roots today - they are not diseased or rotten. Some of the leaves browned a little bit, and dropped, but the rest are OK, just dull and pale color, and curled, - like on my old 2 rhododendrons. I once saw Nova Zembla rhododendrons in one garden center for sale which were the same color and a little curled. Maybe it is common for this variety to have this kind of leaves? But why are the old 2 rhododendrons losing their leaves (almost bold!) and not blooming? They are in partial shade. The new one gets about 6 hours of sun in the summer. I fertilize them once a year in the spring with Holly Tone.

 

[Marck]

Surprisingly, wilting & curling leaves can be a symptom of both of under-watering and over-watering/poor drainage. If there is no drainage issue, perhaps your Rhododendron does need more water. However if you have watered your plants deeply and this symptom persists, then assume there is a drainage issue, perhaps one you have not previously noticed.

In either case, I recommend that you mulch your shrubs with two or three inches of deep layer of fine bark and then try water deeply but not too frequently, especially since Fall is just around the corner. Rhododendron, particularly appreciate a thick mulch layer, but I would go whole-hog mulch that entire bed. Good news is there are floral thyrses developing. Hopefully they will continue to develop. In Spring, fertilize well and apply sulfur. Also do what you can to make sure the shade stays light and dappled.

 

[Mrsclem]

We got 2 from Ohio years ago and planted them here in Maryland. It was at least 5 years before they bloomed. Our are in full shade, never watered or fertilized.

 

[Marck]

If anyone wandering by is curious about the object of discussion, may I present Rhododendron x 'Nova Zembla' in full glory.