Can a Fern Regrow After Being Partially Frostbitten?

Fern Hardiness

• As long as you match the fern hardiness to your growing zone, your ferns should survive winter frosts without damage. The most common problems occur in mild climates where you can grow some of the less hardy ferns. In subtropical climates, an unseasonably cold winter can leave your semitender ferns looking damaged. Though the ferns might look brown and dead, they will often recover from frostbite as long as the roots don't freeze.

Light Frost Damage

• Frost crystals on your semitropical ferns on a chilly morning in winter don't always mean disaster. If some of the fronds turn brown after the freeze, leave them alone until early spring and then cut out the damaged ones near the roots. A damaged fern frond won't continue to grow and repair itself, but the plant will produce new healthy fronds from the roots. Use a knife or a pair of scissors to cut the fronds at the soil line.

Care After Freezing

• After a cold winter, you can help your ferns return to full health with regular fertilizer and a mulch. Wait until spring to start fertilizing ferns even if they are frost-damaged. Starting in spring, after the last frosts have passed, fertilize every other week using a balanced organic fertilizer. Mix 1 ounce into a gallon of water, and pour it onto the soil at the base of the fern. After fertilizing, spread a 2- to 3-inch-deep layer of mulch, such as leaf mold, over the soil round the base of the fern.

Before a Freeze

• You can prevent some frost damage with insulation. Use horticultural fleece to wrap up the fronds of your semihardy and frost-tender ferns before temperatures drop. To protect the roots, pile 6 to 8 inches of mulch up over the soil around the base of the plant. You can use anything you have on hand, such as straw, old leaves, grass clippings or compost. Leave only the protective coverings on the ferns during the freeze. When the weather starts to warm back up, unwrap your ferns.

Heavy Frost Damage

• If all the fronds turn brown and dry up, you won't know how deep the damage goes until spring. Cut back the dead fronds in late winter, and inspect the root area for new green shoots. If you don't see any sighs of new growth by late summer, dig out the frost-damaged fern and replace it. Many tropical varieties won't survive freezing winter temperatures.