Aucuba japonica, commonly known as aucuba or spotted laurel, is cultivated as a broadleaf evergreen shrub in U.S. Department of Agriculture plant hardiness zones 7 to 10, although it may be grown as a container specimen in cooler areas. This plant is prized for its slow growth rate, attractive foliage, drought tolerance and dense, upright habit. Although the aucuba can survive temperatures well below freezing, cold weather or unseasonable freezes in early fall or late spring can cause dieback or leaf drop, warranting protection from anticipated frosts or freezes.
Water the aucuba deeply, as needed, in the days leading up to the anticipated cold spell. Plants that are not under drought stress are better able to withstand cold temperatures than water-stressed specimens. Water the aucuba deeply the afternoon or evening before the freeze is anticipated. Moist soil retains more heat than dry soil and also conducts heat to the soil surface more readily.
Move aucubas that are growing in containers to protected areas, if possible. Garages or porches, even if they are not heated, can provide sufficient protection. Patio areas with brick or concrete walls can retain heat during the day that is later released at night, creating pockets of warmer temperatures.
Place about two or three stakes in the ground around the aucuba. The stakes do not need to be more than a few inches taller than the shrub, and there is no need to pound or set them in the ground very far, as they are temporary. Space the stakes evenly around the aucuba and avoid injuring major roots as you install the stakes.
Drape a woven fabric sheet over the aucuba so it is supported by the stakes and not touching the plant directly. Ensure the material drapes completely to the ground. Plastic sheeting can also be used, but it offers less protection than woven sheeting. Anchor the edges of the sheet with piled bricks, stones, boards or other appropriately heavy objects. If the fabric sheeting has grommets or eyelets, you can push tent stakes into the ground through these holes to secure the material.
Remove any covering the morning after the cold event once the temperature under the covering reaches 50 degrees Fahrenheit.