Causes of curling, yellowing, and browning of Griselinia leaves

My Griselinia hedge has leaves that are curling, yellowing, and turning brown. Some of the plants have dead brown roots, while others seem to be okay. Could this be frost damage, or could the recent strong winds be the cause? Our site is very exposed.

Griselinia leaves falling off is usually the result of frost damage, but the curling, yellowing, and browning of leaves may be due to damage to the stem or roots caused by frost or strong winds. We recommend controlling weeds and grass, watering during dry weather, and observing the plants to see what happens.