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Disease- yellow leaves, brown and black spots

Posted by melofson Washington (My Page) on
Wed, May 9, 07 at 0:44

I hope someone can help me. Late last summer I discovered a disease was rampant in my garden. It affects everything- rhodies, azaleas, escallonias, laurels, magnolia, madrona, even ivy. I cleaned up all the gardens,cut the plants way back, and sprayed Neem oil and another anti-fungal. Now it has come back again full force. It seems to come from the ground up. The plants are otherwise very healthy, until the leaves turn yellow, sometimes mottling before they are fully yellow. Many of the leaves also have brown or black spots/areas. I am really scared I will lose all the plants and some of them are very mature. I have not been able to figure out how to include my photos in this post but I do have digital photos. If anyone is willing to take a look at them, I can email the photos. Thank you.

Follow-Up Postings:

RE: Disease- yellow leaves, brown and black spots

I doubt you have a disease per se - plant diseases tend to be rather specific to individual plants rather than widespread throughout a garden. For example, rhododendron problems generally will not affect laurels, madrone diseases are not common to magnolias, etc. And ivy is virtually disease-free!!

It is far more likely that there is some deficiency or other problem with the soil itself. Poor drainage, chemical contamination, excessive compaction, lack of fertility - any of these can create sufficient stress in otherwise healthy plants so that they perform poorly, display off-color foliage and/or become susceptible to insects or common fungal issues that are secondary to the primary problem.

Do any of these things srike a chord? Have you had a soil test done? Anything different with the garden beginning late last year - a different type of mulch used, a spraying service, perhaps the use of weed 'n feed products on your lawn, neighbors using pesticides, construction activity that could disturb roots or alter drainage?

Unfortunately, soil issues are not easily diagnosed just from photographs, although may provide some indication. You might be better served by hiring a consultant to view your garden personally and evaluate the situation. A local nursery may have a CPH on staff that could offer such a service or direct you to someone with these qualifications or you could inquire at your local extension office.

Feel free to email me the photos if you like (email address on member page) and I'll give it my best shot, but based on what you describe, I truly think a personal, onsite evaluation is your best bet for getting to the root (no pun intended!) of the problem.

RE: Disease- yellow leaves, brown and black spots

Me! Me! Me!...Help me next, GardenGal!

I have the same sort of Azalea problem. Mine is an Encore that I only bought about six weeks ago at a big box. It is still in the "official," Encore, three-gallon pot and sitting on my Zone 7b deck. I have done nothing whatever to this plant except give it a modest amount of water, position it to catch a bit of the winter sunshine, and put it into a storage room (about 40 degrees) during a few nights that dropped into the mid-20s. (It seems to me that it should tolerate that temperature in a three-gallon pot, but I wanted to protect the blooms.) I left it out one night that got to perhaps 29 or 30 and could see some deterioration in the blossoms the next morning, which seemed normal to me. The problem, however, does seem to have appeared rather suddenly with the cold weather.

There are more leaves affected than those shown in the photo, although most leaves still look healthy.

I am new to the forum and, pretty-much to plants, so I don't know much, a bit of groveling that I can do with all sincerity! I'd sure appreciate any thoughts you have on this situation. E-C

Here is a link that might be useful: Sick Azalea photo

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