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Thursday, December 18, 2014

What Are These Weird Growths in My Oleander?

Q. A backyard grouping of four, 12-foot high oleanders that are 18 years old have very strange growths sprouting from the branches so I sent you a picture. Some trees have dry branches.  Others show sections of normal-looking leaves. Meanwhile, a dozen other oleanders look normal. My initial thought was that the strange group of four was not getting the proper watering.  So I have been giving those some extra shots.  But haven't noticed much change since the extra watering started about six weeks ago.

Readers witches broom of Oleander
A. Those clusters of strange growth coming from the stems are most likely witches broom of oleander caused by a fungal disease. It is often spread by pruning shears from plant to plant. It can also spread within the same plant or passed on to new plants when propagated from cuttings.
Witches broom also causes leaf tips to die back but it is usually recognized by those clusters of shoots coming from buds below the pruned area. Usually these distorted shoots grow a few inches and then die.

You may not see these symptoms show up for a couple of months after pruning have been done. This disease is also spread by insects and rainy, windy weather.

There are no chemicals that will control this disease. I would recommend that you cut severely infected plants a few inches above the soil this winter and let them regrow from the base. Make sure you sanitize your pruning shears. If you have some plants there are showing some leaf tip burn then cut these back at least 12 inches below the area showing these symptoms.

Do you want to read more about whitches broom? Click on this link.

6 comments:

  1. I have similar situation with my oleanders. My tenants have cut them too short and seemingly with infected scissors ✂️ so one of them has those little growths along the stems and branches and the other three would have buds but never bloom . They are also looking a bit ill; some stems are green and some brown to grey; bit the usual green color and foliage. Is there anything at all that can save them besides cutting- Even more ? They are otherwise very tall trees; just lack on the foliage ever since that misfortunate pruning.

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    1. Witches broom is a name given to similar kinds of growth on many different plants. The cause is different for each one. A report from Florida recommends that the infected growth is cut at least 12 inches below where the problem is seed and apply Bordeaux fungicide to the fresh cuts. I dont know if this works or not. But if it were me, I would cut down all growth within a few inches of the ground during the winter with a clean and sanitized pruner or saw. Then treat the fresh wounds with Bordeaux fungicide and see if that takes care of the problem. If it doesnt, and regrowth still has it then I would replace the plant.

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    2. file:///C:/Users/intrv/Downloads/104535-Article%20Text-133690-1-10-20170724.pdf
      It is an old publication and there are probably better methods of chemical control but I do not know what they are.

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    3. Thank you so much for the suggestions. It really would be a pity to get the remaining stems cut- they all show the symptoms- whether having the witches broom formation or simply withering lifeless brown looking stems and buds that fall out instead of blooming; I checked the cut places on few stems have weird browning covering and stem looks brittle - yet gets sufficient water to get a bud going on top (10’)

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  2. FYI...the Sphaeropsis sp. disease organism is now called Diplodia and responsible for many different plant diseases.

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  3. Thank you so much for your answer too! I have couple of pine trees too and they are next to each other only I have noticed definitely one of them has diplodia look (I actually took a tip to examine the short curled spikes and brownish growing tips - and this African pine was also doing great; actually had few cones and now it is growing quite funny like.. out of shape (for an African pine type of tree). The pine tree which doesn’t have this Diplodia look on its tips is not struggling and growing much faster!

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