Juniper bushes are hardy, resilient plants famous for enduring tough growing conditions, like droughts and poor sunlight. However, despite their resilience, junipers are prone to several maladies borne from disease and pest infestation which cause browning. Bagworms, spider mites, the fungal disease juniper tip blight, and even dog urine cause the branches and twigs of the bush to discard their vibrant green colour. You can stop a juniper bush from turning brown by first identifying the root and then eliminating the source through insecticides and proper management.
Spider Mites
Hold a piece of white paper under a juniper branch and shake it. Look at any small specks that drop on the paper through a magnifying glass. If you find brown, red, yellow or green eight-legged insects, then your juniper has spider mites.
Spray the base of the leaves, where spider mites feed, utilizing a water hose with a high-pressure nozzle.
Combine 3 tablespoons of vegetable-oil based soap using 1 gallon of water and add the answer to your spray bottle. Mist the bottom of the juniper leaves using the solution. Inspect the leaves after one week and reapply the answer if needed.
Bagworms
Inspect your juniper divisions for elongated off-white or gray bags of caterpillar larvae, indicating that your juniper has a bagworm infestation.
Grasp the bags and pull them in the branches. Destroy the bags by passion to prevent spreading.
Spray the caterpillars that emerged in the sacs using an insecticide containing the active ingredient bacillus thuringiensis. The caterpillars frequently emerge in the sacs in late spring to summer. Spray the juniper every 10 days before the caterpillars are eradicated.
Juniper Tip Blight
Inspect the twigs and branches of the juniper bush in early spring for brown twigs, dead twigs and twigs lying on the ground, signalling juniper tip blight infection.
Wipe the blades of your bypass pruners with 1 part isopropyl alcohol and 3 parts water. Prune back the infected twigs 2 ins to the live wood.
Sterilize the blades in between usage and destroy the trimmings.