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Oklahoma County Cooperative Extension Service

Ask the Determined Gardener

OSU Extension Center

Freddy Hill, Oklahoma County Extension Master Gardener

2500 NE 63rd Street

OKC, OK  73111

405-713-1125

4-10-2018

 

Ask the Determined Gardener

 Rose Rosette disease; is there a soil treatment and how soon can you plant again?    OSU Fact Sheet EPP-7329 describes stages of rose rosette disease and measures to take against it.  The Eriophyid mite (phyllocoptes fructiphilus) is the carrier of this virus.  They can come in on transplants and can be blown in by the wind.  Elongated, discolored stems developing into witches’ brooms, thick brush like growths that are highly-spined and usually dark red.  There is no treatment for the virus but reduction of the mites can come from cutting out and destroying any affected branches, clean any leaf debris and never use a leaf blower around roses.  Some may intersperse other plantings among the roses to reduce cross contamination.   The best practice is to remove any infected roses, roots and all, and clean away any leaf debris in the area.  Locally, removing the plants and soil and replanting has not been effective.  Will Rogers Gardens were famous for its Rose Gardens, but have been unable to reintroduce roses in their beds.  Late fall drift of Glyphosate may cause similar symptoms on the next spring’s growth, but plants can outgrow this damage or you may cut out branches to promote clean rose development.  Researchers are working to develop resistant varieties of roses.

My 28 plant red photinia hedge has black spots on its leaves; how and when should I treat?   Entomosporium leaf spot first appears as small red spots on older leaves, spots grow and become darker.  If you note the date the spots first appear in the spring, plan on treating with a fungicide a few weeks before the date next year. You may cut out heavily affected branches as you thin out the center to promote better air flow.  Water deeply only when needed, but do not water from overhead.  You may re-treat affected plants after each rainfall to reduce spread of this disease.

White mushrooms are growing in my beds and yard, is this dangerous?   Mushrooms are the fruiting body of a fungus feeding off decayed wood, usually old tree roots or buried construction debris.  Remove the buttons before they can create spores, and discard.  There should be no ill effects of this fungus, but we are not qualified to identify any form of mushroom.  Many homes see “fairy rings” of mushrooms which is the expanding area where the fungus has devoured below ground debris. 

My Deodora or Golden Deodora is losing most if its needles:  Some needle drop is common, remember needles are not permanent.  Flagging, large loss of needles is a response to short or long term drought stress.  Affected branches can be removed.  Maintain regular watering only as needed throughout the year.  Many of these plants can’t do well in our Zone-7a climate.

I want to plant an arborvitae hedge.  Generally, these are not successful in our area; especially avoid Green Giant arborvitae.  Thuja orientalis, not occidentalis, is usually a good choice.   Over the years I have tried to establish arborvitae as a sight hedge but have been unsuccessful.  I chose Nelly R. Stevens holly, which can grow to 25ft but can be pruned to different heights. 

For more gardening information feel free to visit our website at http://oces.okstate.edu/oklahoma or call the OSU Extension office at 405-713-1125. 

 

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