Freezing Damage to Geraniums

Protection

• When the temperature is expected to drop to the low 30s F or below, which is called a freeze, protecting your geraniums can save them from damage or make the difference between major damage and only slight injury. Move potted geraniums indoors or to a different protected area. Geraniums in the ground can be covered with burlap, several layers of newspaper or blankets. Tarps and plastic should not be used as covers because the cold temperature will transfer through the tarps or plastic and damage the geraniums. Small geraniums may be covered entirely with dry leaves, pine needles or straw mulch.

Frost

• Geraniums are considered tender plants and can be affected by temperatures in the mid-30s F. The temperature, its duration and the amount of moisture in the air can create frost, which can damage geranium leaves and new shoots. Frost-damaged geraniums exhibit limp, wilted and discolored leaves. Keep the frost damage on geranium plants as future protection until the threat of frost passes. When temperatures warm, remove the frost-damaged parts from geraniums and new growth will soon appear. Geraniums can survive even severe frost damage.

Freeze

• When geraniums experience freezing temperatures, their leaves become limp and their stems become mushy, eventually turning black and rotting. Younger and smaller geraniums are more affected by freezing temperatures than older and bigger geraniums. Leave damage from a freeze on the plants until all danger of frosts and freezes passes; that will protect them from further injury. Waiting for the temperature to warm and the growing season to begin is helpful to identifying the extent of damage and removal of all the damage. If the freeze was cold enough to freeze the ground and roots of your geraniums, the plants may be dead.

Winter Preparation

• If you live in a regions that periodically experience cold weather during winter, then taking precautionary measures may help your outdoor geraniums survive. Stop fertilizing and pruning your geraniums in late summer. Fertilizing increases new growth, which is easily damaged by cold temperatures. Keeping extra growth on the plants by not pruning protects the inner growth. Decrease watering to allow the geraniums' soil to be barely moist. Very wet and soggy soil may freeze and kill geranium roots, and drier soil acts as an insulator to roots. Cover small geraniums entirely with dry leaves, pine needles or straw before winter.