The common fig, Ficus carica, is a Mediterranean native that requires protection to survive winter outside its natural range. While mature fig trees can tolerate a light frost, temperatures consistently dipping below 20°F (-7°C) cause significant damage, especially in colder temperate climates like USDA Zones 7 and below. This damage typically manifests as stem dieback, which reduces the following year’s fruit production, and in severe cases, can kill the entire plant. Providing a protective layer insulates the woody growth and the crown, preventing cellular damage caused by hard freezes and ensuring the tree can regenerate successfully in spring.
Preparing the Fig Tree for Dormancy
Preparation for winter begins in late fall, after the tree naturally sheds its leaves and before the first hard freeze arrives. The tree must be fully dormant and “hardened off” to withstand cold temperatures effectively. To help induce dormancy, growers should significantly reduce or completely withhold water and fertilizer application starting in early autumn.
Allowing the tree to experience a few light frosts further signals the plant to enter its resting state and helps the wood lignify, or toughen. Once the leaves have dropped, the tree is ready for structural pruning, which serves two main purposes. Removing any dead, weak, or crossing branches improves the tree’s overall health and significantly reduces the total volume that needs to be covered.
Choosing and Applying the Protective Layer
The primary goal of winter protection is to create an insulating air pocket around the fig tree while managing moisture to prevent rot and mold. The most common and effective method for in-ground trees is to construct a protective cage around the bundled branches. Begin by using twine or rope to gently gather and secure the tree’s branches into a tight, upright column, making the overall structure manageable.
Next, a sturdy frame must be built around the bundled tree using materials such as chicken wire or three to four wooden stakes driven into the ground. This frame should stand several inches away from the bundled tree to establish the air pocket that will hold the insulating material. The type of insulation used inside this cage is shredded leaves or straw, which are lightweight and trap air effectively.
This insulating material is then tightly packed into the space between the bundled branches and the exterior frame, surrounding the tree from the base upward. The final step involves wrapping the exterior of the structure with a waterproof yet breathable layer, such as burlap, roofing felt, or a light-colored tarp. Ensure the outer material does not directly contact the inner insulation or the tree itself, as this can trap moisture.
For the outer layer, avoid non-porous plastic sheeting that completely seals the tree, as this prevents air exchange and creates a high-humidity environment conducive to fungal growth. The top of the protective structure should be covered to shed rain and snow, but a small opening should be left or a bucket placed upside down to allow trapped moisture vapor to escape. For smaller fig trees, an alternative method is to gently bend the trunk and branches to the ground, secure them with stakes, and cover the entire structure with a thick layer of mulch or soil, which leverages the earth’s insulating heat.
Removing Winter Protection in Spring
Uncovering the fig tree in spring requires careful timing and a gradual approach to prevent shocking the plant after months of protection. The protection should be removed after the danger of the last hard frost has passed, which is in late winter or early spring when nighttime temperatures remain consistently above 20°F (-7°C). Removing the covering too early risks exposing tender growth to an unexpected freeze, while leaving it on too long can cause the tree to prematurely break dormancy in the warm, moist interior, leading to rot.
A staged removal process is beneficial to help the tree acclimate to the changing conditions of sunlight and temperature. First, remove the outer waterproof layer, such as the tarp or roofing felt, on a mild, overcast day to prevent immediate sun scald on the pale, newly exposed bark. This allows for increased air circulation while still maintaining some insulation from the inner layers of straw or shredded leaves.
After about a week, once the tree has begun to adjust to the light and air, the inner insulating material and the frame can be completely removed. Immediately after uncovering, inspect the trunk and branches for any signs of mold, rot, or physical damage that may have occurred over the winter. The twine holding the branches together should be cut to allow the branches to slowly expand back to their natural shape, preparing the fig tree for the start of its new growing season.