Anyone know what this is and how to treat it. We have a hedge row about 10 feet tall and 40 feet long. I just noticed the discloration of a few leaves, some have black spots - see picture. All the other leaves are bright and healthy looking.
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Thanks for the input. I have replaced the pictures with closeups top and bottom of leaves.
For TheLorax - Leaf disease on fine line holly-c loseup pics
Last edited by Raym on Thu May 15, 2008 11:30 pm, edited 6 times in total.
Don't need photos of the healthy leaves. Your photos of the diseased leaves are good but too small to see much. At first glance it looked like holly tar spot but when I enlarged the image it was sorta looking like sooty mold. Do you recall having seen any yellowing of the leaves before they began taking on that appearance? Any chance you can take more photos closer up of the tops of the leaves as well as the undersides of the leaves please?
Thank you for sending me additional photos privately. I've looked at all the photos of your Ilex cornuta 'Fine Line' and enlarged a few and am beginning to think you've got a double if not a triple whammy going on here. Ideally, you might want to nip off a diseased portion of your plant to take into your extension office before doing anything. Let somebody from your area eyeball in person what you've got as they would be in the best position to offer suggestions.
In lieu of taking a sample in, you might want to consider pruning out and burning all branches with leaves that are darkened from what I believe may very well be a fungal infection. Rake up any leaves that fell to the ground and burn those too. Spray any pruners you use with Lysol to help limit the spread of what ever it all is you've got going on. Spray your rake too. What you're trying to do is to remove potential reservoirs of disease. Now that you've removed branches and leaves that were visibly diseased, go back and look at all the plants and see if there is a need to thin out the area to increase air flow as well as to help reduce the spread of disease from plant to plant. Crowding plants can stress them which leaves them vulnerable to disease. Appears to me as if you've additionally got a scale problem and possibly a tertiary bacterial issue. Again, it would be best if you could visit your extension office with an actual cutting of what you have photographed.
It might be best to steer clear of chemicals right now. Horticultural oils will probably be your best route. A tablespoon of horticultural oil plus a tablespoon of baking soda mixed into a gallon of water may help alleviate some of the issues you've got going on there. One of the brands of horticultural oils that I use is Bonide's All Seasons horticultural oil but I have used another brand of summer horticultural oil. Might have been a Safer's product.
Water all of the same species plants well before you spray. Wait for a nice overcast day and spray all of the plants in the area of the infected plants and be sure to get the undersides of the leaves well. Repeat in four days. Repeat again after another four days after that.
Little blurb on why you would want to choose a superior or summer horticultural oil at this time of year-
https://leon.ifas.ufl.edu/News_Columns/2003/012603.pdf
While you are spraying your plants, begin researching how best to meet the cultural requirements of those plants.
Will you please come back and post how the plants are doing in a few weeks?
In lieu of taking a sample in, you might want to consider pruning out and burning all branches with leaves that are darkened from what I believe may very well be a fungal infection. Rake up any leaves that fell to the ground and burn those too. Spray any pruners you use with Lysol to help limit the spread of what ever it all is you've got going on. Spray your rake too. What you're trying to do is to remove potential reservoirs of disease. Now that you've removed branches and leaves that were visibly diseased, go back and look at all the plants and see if there is a need to thin out the area to increase air flow as well as to help reduce the spread of disease from plant to plant. Crowding plants can stress them which leaves them vulnerable to disease. Appears to me as if you've additionally got a scale problem and possibly a tertiary bacterial issue. Again, it would be best if you could visit your extension office with an actual cutting of what you have photographed.
It might be best to steer clear of chemicals right now. Horticultural oils will probably be your best route. A tablespoon of horticultural oil plus a tablespoon of baking soda mixed into a gallon of water may help alleviate some of the issues you've got going on there. One of the brands of horticultural oils that I use is Bonide's All Seasons horticultural oil but I have used another brand of summer horticultural oil. Might have been a Safer's product.
Water all of the same species plants well before you spray. Wait for a nice overcast day and spray all of the plants in the area of the infected plants and be sure to get the undersides of the leaves well. Repeat in four days. Repeat again after another four days after that.
Little blurb on why you would want to choose a superior or summer horticultural oil at this time of year-
https://leon.ifas.ufl.edu/News_Columns/2003/012603.pdf
While you are spraying your plants, begin researching how best to meet the cultural requirements of those plants.
Will you please come back and post how the plants are doing in a few weeks?