Juniper Tips Dying?
If they are, you likely have juniper tip blight, or phomopsis.
This is a fungus that attacks the growing tip of the juniper, usually in spring when the temps are mild, around 60 F / 15 C or so, and during humid or wet weather. It attacks many species of juniper. Native North American junipers like Rocky Mountain Juniper are from arid areas and are particularly susceptible, but it is also found on shimpaku junipers. Needle junipers seem least susceptible but they also can be attacked.
Juniper Tip Blight, or phomopsis
This is a serious disease that can kill the branch and ultimately the tree. Do not ignore it if you have it. Again, this is a disease most active in the spring although you might see the fungal damage any time of year. Cutting away affected areas helps track its progress.
If you’ve ever seen ground cover junipers with dead patches, it’s very often this fungus. Other tip blights may look similar, like kabatina, but phomopsis is the main one.
Once you have it this disease can take a while to get rid of, often taking a year of spraying. Control is with fungicides, sprayed late winter through late spring, often 2-3 times a month. Go for complete coverage, to dripping. Common fungicides like Daconil won’t work with this disease, you will need others like Mancozeb, Heritage, or Cleary’s (always read labels very carefully, dosages and scheduling differs for all of them). Those who live in moist climates may need prophylactic sprays in the springtime to stay on top of the problem and to have disease-free juniper bonsai.
If you’re not sure you have this fungus—or any disease—it’s wise to get confirmation with a lab test. Try agricultural universities and private tree care professionals, many have labs that can diagnose pathogens. General guidelines for handling samples: Cut off some fresh, diseased areas, place a lightly damp towel in a ziplock bag and seal, label it carefully with date and species, and put in the mail immediately—overnight service to the lab is usually recommended. If this is impossible refrigerate specimen until sent. Close up photographs are also often helpful. Labs will usually come with their own instructions, however.
Michael Hagedorn 
13 Comments
another treatment you may want to consider is Spectracide lawn fungus treatment. the active ingredient is propiconazole which, I’ve found to be quite effective. there is no mixing involved. Black Flag has a product with a similar concentration of propiconazole and is 1/3 of the cost.
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Yes, propiconazole is a newer fungicide and it does control some tip blights.
I have been fighting Phomopsis on a Tsukumo Cypress for two years now. It has taken quite a toll. Recently started with a rotation of Clearys and Mancozeb and may be seeing some better results. One of my Shimpakus that is in relatively close proximity to the Cypress is exhibiting some indications of blight but overall the Shimpakus do not seem to be anywhere near as susceptible as the Cypress.
This is also a problem, several other plants get phomopsis including this cypress and Cryptomeria.
Could you please comment about Gymnosporangium/ Chaenomeles Japonica or quince rust/cedar rust? How do you protect yours junipers and Rosaceae family bonsai?
There are fungicides that will help control rusts if you want to grow both types of plants. I am a bit shy of giving brand name advice here, though many fungicides cover rusts. Read the label carefully!
Hola, encontraste solucion para eliminar el hongo
Michael this is a helpful blog on tip blight. I have an issue with dead patches on my Shimpaku coming up from the base, inside and the tips die last.
Peter, are you referring to the Black Flag Extreme Lawn Insect Killer Plus Fungus Control Granules? It seems to be available at True Value Hardware, whereas I’m having a harder time finding Mancozeb, Heritage, or Cleary’s. Michael have you found a convenient source for these?
Happy spring, Michael!
I have tried to find a product at my local suppliers that contains mancozeb, but the only available is in the mix of Daconil, ready to use in a spray bottle. I noticed that you said Daconil doesn’t work; is that specific to the Daconil concentrate? Or is the amount of mancozeb in Daconil too dilute?
Hi Laurel—Mancozeb is the product name, not an ingredient. Try Heritage or Cleery’s if you can’t find Mancozeb.
Thanks for the clarification, Michael!
Following up to my problem of a year ago, i followed Michael’s advice to cut away the infected areas. Then I did spray and drench with Daconil for 2 times/month until summer, and it seems to have stopped the progression (whew!!). So far this spring my juniper is looking fine.
For juniper tip blight is a tricky one to get rid of, often taking a couple years. Heritage, Mancozeb, and Cleery’s are better fungicides for its control. But I’m glad you’ve managed to control it.