How To Get Rid Of Sooty Mold on Azhalea plants?
First time, I have at my home all Azhalea plant leaves and stems have powdey Black Sooty mold and some dendralions are dying and have white fungus on stems
There appears to be a scale insect pest (white spots on the stems). The scale is a sucking insect that excretes a sweet honeydew on which a 'sooty mold' grows. The sooty mold is not harmful except to shade the leaves from sunlight, but the insect pest at this level is a serious condition.
I believe the plants are susceptible to the pest infestation due to nutrient deficiencies, indicated by leaf discoloration which is characteristic of poor soil fertility.
I recommend that you fertilize with a slow release complete organic fertilizer like the Dr Earth Acid Lovers on this page:
http://www.fertileearthlandcare.com/fertilizers/
Professional applicators would soil drench with a systemic insectide with dinotefuran
https://www.domyown.com/alpine-wsg-p-2876.html?sub_id=14696
I'm not sure about the other plants. The white material could be lichens or a fungal secondary growth on the dead stems, and not the cause of the mortality.
I have many bushes planted together and I'd like to prune them lower to the ground, substantial pruning (6-8 inches). when is the best time to do that, and is that too much pruning for 3' bushes?
The ideal time to prune azalea is right after it blooms; otherwise, you risk trimming off next year's blooms. More information is below. https://www.gardeningknowhow.com/ornamental/shrubs/azalea/pruning-azaleas.htm
Detailed information on different types of pruning is here: https://www.rhododendron.org/v47n3p136.htm
My formosa is 6' tall, in a large tub. It stands out in the sun all summer and I bring it into my frost free conservatory in the autumn. With the same problem last year, I was advised to remove it from it container, and saw off the bottom half of the root ball. fill with fresh compost and replace. This I did, and during the summer, it was covered in buds. However once again, all of the buds have fallen off without opening?
I do remember this. Have you made sure to remember to drill holes in the container? without having proper drainage it will throw off the soil environment.
Other than this, and depending on the type of compost, and what animal manures are in it, there could still be too much nitrogen and not enough phosphorus and potassium.
Another thing that is common with this issue is an extreme change in environment. I wouldn't recommend full sun since it will be moved into an area in which the windows filter out some of the spectrum of light. Even if it receives direct sun through the window, a test on light intensity and spectrum will reveal quite a loss.
This drastic change will prevent flowering as well.
Have you checked the soil pH? These will not like to go above 6.0 in pH. This will certainly cause an issue.
Try correcting these last few issues and it will continue to flower.
We have two newly planted evergreen bushes near our condo, and I am wondering what they are. Also, I want to thank all of you who have answered my questions in the past. You are a great group!
They are Azalea, or Rhododendron. These have recently been reclassified together into one group, so you can now take your pick on what to call them! There is a little trick to knowing exactly which is which, but it requires looking at how many stamen there are per flower. Either 1, or 2. That's it.
Good fall blooming of my encore azaleas, then in late November single plant showed leaves turning scarlet gradually changing to orange, then brown, and shedding. Accelerated death of blooms. So far I cannot identify pests or specific leaf spotting. Process is progressive and plant may be dying. My location is a small barrier island, mid-coastal N. C. Fall has been mild with probably average rainfall. Plants are mature about 10 yrs. old and previously healthy. Please share thoughts/ suggestions. Thank you, John Marriott
Is this plant in the same area as the rest? if it is not, then I would say that the pH of your soil is thrown off, and can be corrected with a little dolomitic lime. If it is in the same area then I might suggest that it could be a cultivar specific infection, which will require wettable sulfur, and dolomitic lime to correct. These azaleas are quite different than other cultivars, and may require different care.
Alternatively, it may, simply, require some fertilization.
Here is an article that will help you: https://www.gardeningknowhow.com/ornamental/shrubs/azalea/common-azalea-problems.htm
When is the best time to fertilize, and then to prune?
Fertilizing is often not required if you mulch regularly, but you may do so in early spring if you are noticing deficiencies. Pruning them can be done anytime between the time that the old blossoms fall off and the new start to grow.
This article will give you more information: https://www.gardeningknowhow.com/ornamental/shrubs/azalea/azaleas-noteworthy-shrubs-for-any-garden.htm