There are a number of diseases that could be the culprit; there could also be a problem due to a lack of nutrition in the soil. Terracotta pots placed on your Terrace or Patio look fabulous containing carefully clipped box balls and topiary triangles. There are several reasons why this may happen. Q. Box Blight . Actually, there are numerous reasons why an evergreen might start turning brown. I’m not sure what I have done wrong, and would love some advice on how to care for them back to full recovery. When there are whole brown leaves on a plant, this can indicate several dozen problems; but when just the sides or tips of the leaf turn brown, there is only one problem — the plant is stressed. These can occur on the stem from the soil line to the shoot tips. Most commonly brown leaf tips or brown edges on leaves are caused by the plant not getting enough water. If your plant isn’t over-watered but you’re still wondering why rosemary has brown tips, look to recent changes in lighting conditions. In fact, winter becomes the most common season for spotting brown foliage on otherwise green boxwood shrubs. I have tried insecticide and fungicide to control the problem. Firstly lets have a look at the problem from a web site on the net: Two of my dwarf Alberta spruce has a problem that causes the needles to turn brown and fall off. Junipers (Juniperus spp.) The same plants have been used for topiary as well. The same watering policy for outdoor plants should hold for potted rosemary — it should never be left in a saucer of water or the soil allowed to remain wet. Dying Topiary ... ago. You will have to Test the trunk with your nail till you get to a green part. Exposure to cold winter winds, dry conditions and frost contributes to boxwood leaves turning brown, reddish-brown, orange or yellow. Before you can take any steps to fix the problem, you need to figure out why your tree is turning brown. Box plant leaves will go a coppery brown colour if the plant is short of nutrients, or if it is exposed to very cold winds, or to prolonged frosty weather. Then a disease appeared which has caused great problems for both nurseries and home gardeners. They have survived extremely cold winters. the other is. My Juniper Needles Are Turning Brown & Falling Off. If it is dry brown and not green it is probably dead. hi all. I have feed and pruned them each spring. I have a pair of box topiary at my south facing exposed front door. Folks, if you have leyland cypress trees, then you've probably noticed that at times, part- or all of the trees- may turn brown. I recently noticed some brown limbs and looks like dying. Black, elongated, streaking lesions may also be visible on the stem. This process, known as bronzing, does not cause permanent damage to boxwood shrubs. Boxwood (Buxus) are wonderful evergreen plants to formalize the edge of a border with a low hedge or grown into a larger shrub to make topiary shapes. are needle-leaved evergreens that are used in many landscapes. Why is the tree turning brown? The top of the topiary may be dead (die back). Potted Rosemary Turning Brown. Scape the trunk on the top with your fingernail. Cut the trunk at this part or the die back will continue down the trunk and kill the plant completely. they have been there since April but one of them is getting patchy brown leaves. These spots eventually grow larger and coalesce before turning brown or straw-like and dropping to the ground. Brown leaves on Box plants, How to treat Box Blight Beautiful Box Trees.