With people taking more interest in their landscapes and gardens during the past 18 months, they often have questions as they pay closer attention to the plants in their care. Although homeowners should always be on the lookout for pests and diseases, if plants are healthy and well-cared for, problems are rare. And, sometimes a “problem” is not at all what it seems.
A recent column discussed the natural yellowing and shedding of the inner third of white pine needles every fall. With other, more densely growing evergreens, the yellowing of older foliage (needles are modified leaves) is not as obvious. Many conifers hold their needles for years and when they yellow, they are hidden out of sight in the interior of the shrub. Spruce needles last for up to eight years before browning and dropping off, and with the typically dense growth of a healthy tree, are not noticeable. Yew and boxwood foliage last even longer, finally yellowing when deprived of sunlight deep in the interior of the plant.
I received an email recently from a lady quite concerned about the ‘Emerald’ arborvitaes she had planted as a privacy screen by her patio. She thought they were dying when she noticed so many brown areas deep inside the plants. They were completely hidden by the thick green growth of the exterior. I assured her that this was entirely normal, with nothing to worry about. Note: Arborvitaes are very shallow-rooted and need watering during dry spells. This year’s abundant rainfall was very welcome to keep them lush and healthy!
The first photo above shows the typical exterior growth of a healthy arborvitae. The second photo shows the interior of the same shrub with the green foliage pulled aside. Absolutely nothing to worry about!
Happy gardening!