In case you’ve got one privet shrub (Ligustrum spp.) Or a hedge composed of these evergreen shrubs, watching leaves begin to turn yellow can be troubling and might be a warning sign of a problem that requires attention. The very first step is to identify the cause of the leaf discoloration, which can stem from a disorder, a cultural issue or infestation with a pest that damages leaf. Oftentimes, simply adjusting the way you look after your privet can take care of the issue.
Privets are susceptible to a number of fungal disorders, such as leaf spot and root decay, that can cause leaves to turn yellow. After the issue is severe, leaves might blacken and die. Proper spacing of plants helps ensure good air flow, so that leaf dries quickly after rain and fungus does not grow. The Japanese privet (Ligustrum japonicum) becomes approximately 8 ft wide, while the California privet (Ligustrum ovalifolium) can be around 15 feet broad, so if you are growing either kind for a hedge, space plants at least 8 and 15 feet apart, respectively. In case your privets are already implanted too closely, remove every other plant in a hedge to improve air flow. You can also discourage fungal growth by watering with a soaker hose or drip irrigation, to maintain foliage dry, and by protecting plant debris from under plants regularly.
Privets are susceptible to a number of pests that may cause yellowing of leaves. For instance, microscopic spider mites weave visible webs on leaves, causing them to yellow and die back if not controlled. Other pests such as thrips and whiteflies can also infest privets. If you analyze the plant, then you may see these tiny insects hopping and flying between leaves. They suck plant juices, damaging leaf and causing leaves to yellow and eventually drop. These soft-bodied pests can be controlled by spraying the privet with insecticidal soap, diluted at a speed of 6 tablespoons per gallon of water. Wet all plant parts till they’re dripping, ensuring that you cover both the surfaces of leaves, and repeat the program every two weeks as required.
If you see yellowing of leaves on a privet that’s accompanied by spindly, inferior new development, but no other signs of disease or pests, the possible cause is inferior soil nutrients. A deficiency in any one of several vitamins may cause yellow leaves; such contain sulfur, potassium and potassium, as well as a number of the trace minerals, such as magnesium and manganese. Keeping plants well mulched with an organic material such as compost or composted manure can help fix these issues, but that can take several seasons. Privets don’t typically require regular fertilization, but if you see signs of mineral deficiency, fertilize the plants in early spring using a granular 10-10-10 formula which also contains trace minerals and is labeled suitable for broadleaf shrubs. Apply at a rate of 2 to 4 pounds per 100 square foot of area under the plant’s canopy, but assess your label for additional directions.
The California privet and Japanese privet are deciduous shrubs which are usually tough and hardy. They develop in U.S. Department of Agriculture plant hardiness zones 5 through 8 and 8 through 10, respectively. Both are flexible garden plants which thrive in shade or sunlight and attract butterflies during the growing season. However, both plants are potentially invasive in some regions of the U.S. and might spread from self-seeding. Japanese privets can also spread and eventually become large thickets that can invade naturalized places; for this reason they are not great choices to plant near the edge of a forested location.