I am having a problem with my Pyracantha hedge. Every spring some of the leaves turn yellow, develop black spots and then fall off. I spray every winter with a horticultural oil but no other treatments. This year it is really bad. It does not sound to me like fire blight or mites or scab when I read the descriptions but I am not sure. Can any one advise?
Mine do that when we've had too much rain and the soil doesn't dry out for weeks on end. (Like now.) They do come back, though, so try holding off on watering.
Many of them around here look like yours because it's been very wet for so long and the soil is saturated.
An update on this question. I have subsequently found out this is "leaf spot" due to Entomosporium, a fungal infection. it is worse in the spring due to the winter rains and of course this year worse than ever due to the heavy rain in Califonria this year.
Sorry Jack, I am tagging on to your message because I cannot find the "start new topic" button!
I hope someone can answer my question.
3 years ago I planted nine Kasan pyrancantha from Monrovia Nursery. They were in excellent condition as everything I have ever bought from them are. But this year because of the excessive heat and rain we have been having they look to have developed the dreaded fire blight. This variety is supposed to be resistant to fire blight but it looks very much like it to me. I have enclosed a photo, please advise someone.
It doesn't look like your Pyracantha's have fireblight to me...at least not from the photo you posted. If they did have fireblight, you would see browning foliage on the tips and growing back in towards the main part of the plant.. The foliage in the photo appears to be fine.
The dried berries that show in your photograph appear to be ones that just didn't fall from the plant, or possibly got broken from the stems but didn't completely fall off.
I have three large P's that exhibit what yours are doing quite often and the berries drop eventually. Mine tend to what yours are doing when it's very hot, like it's been lately, but the vast majority of the fruit looks fine...and there's always SOME that turn brown and remain on the plant, but they do drop eventually.
Can you post more pictures and show more of the foliage, or is your problem just with the fruit ?
Thank you Jasper, I wrote to Monrovia and this is their reply:-
"It appears that your Pyracantha Kasan did have fire blight. From your photo it also appears that fresh new leaves are emerging. You can clip off the dead stems but you should disinfect your pruning shears after each cut. Disinfect by wiping the blades with rubbing alcohol or you can purchase a disinfectant labeled "Physan" Fire blight enters the plant stems through the flowers in spring. The disease is spread by bees collecting nectar from the flowers. The conditions you described of excessive rain and high humidity add to the conditions that are conducive to this bacterial disease.
Kasan pyracantha is more resistant to fire blight but under adverse conditions it can also be infected. Treat your plants with a copper based product that is labeled fire blight. Your local garden center can provide you with the correct product .
Since your plant is not in flower, one treatment now should be sufficient. Take care to use the proper dilution and apply according to the label instructions. Next spring, spray your plant every two weeks while it is in bloom to prevent re occurance."
Customer Care at Monrovia
What the gardener did not mention, is that the copper based treatment contains streptomycin, an antibiotic. I would prefer not to use an antibiotic, and wondered whether anyone knows of an organic treatment for fire blight please? Note, he also uses the past tense, I thought fire blight was a killer and once a plant developed it there is no cure, but his post suggests the pyracanthas WERE infected but not now?
I will take more photos when I can get outside, as usual there is a thunderstorm brewing.
