|In this large planter box our landlord planted a Hollywood Juniper in full sun but within a week it went brown. I gave it water every other day but still went brown. What causes this to happen?|
|I'm sorry the juniper didn't perform. It's August, and I'm assuming that it was planted recently. Any plant will struggle if transplanted in full sun at this time of year, even well-adapted desert plants. And, juniper is not particularly well-suited, although they do grow here. Soil in any type of planter, even large ones, heats up tremendously and roots basically "cook" if not kept consistently moist. They can't absorb sufficient water to keep the above ground foliage green and healthy. Watering every other day may be insufficient. It's also essential that water soaks down through the entire rootball's depth and width. Assuming the juniper was in a 5-gallon pot when transplanted, water should soak 2 feet deep. If "sprinkled" lightly with a hose for a few minutes, for example, water will only penetrate the top layer of soil. If you feel the soil moisture was adequate, another possibility is that the foliage turned brown from salt burn. Salt burn shows up as yellowing, browning along leaf edges, and leaf drop. Desert soil and water both contain salts, which can accumulate in the root zone over time. This salt buildup forms where the water stops penetrating. Short periods of watering cause salts to build up in the top layers of soil and damage or kill your plant.
It's always nice to have greenery, but if you choose to replant another juniper, I'd suggest waiting for temperatures to cool in the fall before transplanting. October is prime planting time in the low desert for almost every type of plant. (Only palms prefer summer planting.) After transplant, layer organic mulch (compost, wood chips, leaves) on top of the soil to maintain soil moisture and moderate temperatures. I hope this info helps.