What can I do for evergreen bush with brown patches?
Hi, the evergreen bush in our back yard has some brown patches(see first picture). I first noticed them last summer, they are still here this year. The bush is between two yards so it is not in an area exposed to salt over the winter. The outside of the bush looks healthy and has some new green growth, but some of the branches on the interior of the bush look bare and dead (see second picture). I have trimmed away all of the brown patches. What else can I do to keep the bush healthy? Christine
Lake County Illinois
Since your evergreen began browning before the winter, the browning is not likely due to winter damage. The possible culprits are insects, disease, environmental stresses and maintenance issues.
1) Identify your species of evergreen. Identification will help narrow the suspects of decline. Each species has its own common problems.
2) Look at similar trees in the community. If all the pines in the area are affected, environmental stress is more likely. Needle browning on a wide variety of evergreen plants such as pines and spruces typically is also environmental and not an infectious disease or insect problem.
3) Prune any additional browning.
Cut out dead limbs back to the main truck or stem. This way the plant will not use energy to heal a limb that cannot be saved. Use loppers or a tree trimmer to take out the limb.
Snip off diseased limbs at least 3 or 4 inches back from the diseased area to insure that you remove all the disease. Rake up needles or leaves that have fallen to prevent the disease from spreading to other areas of the garden.
Check the dampness of the soil around the bush. It could be stressed from lack of water. The soil needs to be damp down to a depth of at least 3 or 4 inches. Water the soil to improve the moisture content.
Recheck the soil to see if the water reached the level you needed. Apply more water if necessary. Water several inches per week until dry weather subsides.
Mulching trees with an organic mulch, such as wood chips, can also help maintain soil moisture.
If browning persists or worsens:
Test the soil around the shrub. Dig 8 to 10 inches and remove soil for the test kit. Place the soil in the test containers, and follow the directions on the kit to test the levels of nutrients in the soil.
Adjust the soil nutrients if the tests show that the levels are low. Pay close attention to the pH level. Evergreen plants prefer a slightly acidic soil. If the test shows that it is alkaline -- 7.0 and above -- then apply an acid-based fertilizer to improve it. However if the test shows an extremely acidic soil -- 4.0 or lower -- then apply an alkaline fertilizer to lower the acid level.
Here is a list of soil laboratories: http://extension.illinois.edu/soiltest/