Knowledgebase
Moonlight Junipers leaves turning brown, branches still flexible and not dried out #875942
Asked July 04, 2024, 3:13 PM EDT
I have two sets of moonlight junipers. Four planted on the NE corner (planted in 2023) and 8 planted on the SW. (7 planted in 2018 and two planted in 2023). I fertilized the trees when planted and fertilized with miricle grown evergreen spikes for the first time 2-3 weeks ago. I also used the spikes to fertilize my colorado baby blue spruce and they are doing great). Even the established junipers planted in 2018 are showing effects but the young ones planted in 2023 are browning more rapidly. The browning started weeks before fertilization and althoughmoonlight spruce are supposed to need very little water once established, I started deep watering thinking it was the early hot weather/wind and the trees needed additional water. The leaves seem more brown than yellow so I did not think it was any type of blight but I'm not sure. Are they just needing a lot of supplemental water because of the heat and lack of rain? They are planted in heavy clay soil but I amended the planting area when they were initially planted
Jefferson County Colorado
Expert Response
Thank you for contacting Extension with your question.
The heat and dryness have certainly stressed out many trees in our region. You are correct that your junipers are fairly drought tolerant once established.
However, there may be a disease process at work here.
Phomopsis tip blight damages new growth and succulent branch tips of junipers from mid-April through September. Older, mature foliage is resistant to infection, and therefore, most blighting occurs on the terminal 1O to 15 cm of the branches. Affected foliage first turns dull red or brown and finally ash gray. Small gray lesions often girdle branch tips and cause blighting of foliage beyond the diseased tissue. Small, black, spore- containing fungal fruit bodies develop in the lesions. Use a hand lens to more easily view these diagnostic fungal structures. If you wish to have a clinician rule out or confirm this, please consider bringing in a sample to the office at the Jefferson County Fairgrounds. (Collect a 12-24 inch long branch with leaves attached. Sample should show transition from healthy to affected foliage.)
You will want to prune off the dead twigs going about 2 inches into healthy wood. Burn or bury these twigs, or put them into the trash. You want to choose a dry day for this when the plant foliage is completely dry and humidity is low. Sterilize the pruners with rubbing alcohol between cuts. Make sure to water only the roots of these trees- avoid wetting the foliage or brushing up against the foliage when they are wet. There are some fungicides that are labeled for twig blight on junipers, and these should be applied in the early spring. Read more about juniper blight here: http://plantclinic.cornell.edu/factsheets/junipertipblight.pdf
Best regards,
Cindy G.
