Whether your juniper bushes are your pride and joy, or they simply line your landscaping along the background, you want them looking healthy and strong. This can be tricky, however, when your juniper suddenly turns brown and starts to look like it might be dying in a matter of days. While some browning is natural as a juniper ages, quick browning like this is trouble. To stop juniper bushes from turning brown you'll need to treat them for the spider mites that have invaded.
Inspect your plant for the tell-tale signs of mites such as a dusty or gray appearance caused by their webbing. If you can spot your juniper turning dusty early, you may be able to prevent mites from sucking the life juices from the plant and turning the bush brown.
Spray a high-powered stream of water over the entire plant to knock the mites off the needles. As you spray, change the angle you are spraying at to catch the undersides of the plant as well as the top.
Continue to spray your juniper bush with water every couple of days for three to four weeks. Keep checking on your juniper each time you spray to see if the gray areas of needles are starting to come back to green and that any browning that had started hasn't worsened.
Use a miticide, not an insecticide, on your juniper if the water doesn't seem to be having the results you're looking for. Follow the directions of the packaging for application methods and amounts, re-treating as needed according to the manufacturer's instructions.
Wait for the brown and gray areas to get under control and continue to examine your tree regularly to monitor damage. Clip away any significantly bare stems with pruners just after a healthy, green branching, leaving behind only the new green growth.