Winterizing Your Fig Tree

There's nothing like a fresh fig! Despite our northern climate zone and the need for winter protection for these subtropical fig trees (Ficus carica), we optimistic gardeners are determined to grow figs for their luscious fruit. But edible figs, even the most cold-resistant varieties, only tolerate temps down to 20°F, and will suffer true winter damage below 15°F (except 'Chicago Hardy'). So what methods will help you winterize both containerized and already established in-ground figs?

Take a deep breath. Don't worry if your tree dies back to the base. The main, most productive, and most flavorful crop grows on the current year's new growth and is harvested in late summer to early fall. Many figs adaptable to colder climates do not usually produce an early breba crop, which grows on the wood of previous years. Fig trees will recover and produce many branches from the roots in a preferred shrub-like, basally-branched configuration, rather than a single trunk form.

Containered Figs: Bring Indoors

If you have containerized fig trees, you have more options for protection, provided your container can be moved indoors.

• After a hard frost, remove all remaining leaves and unripe figs.
• Place containers in an insulated, unheated, preferably dark room, garage, or cool basement. If the space is not dark, you can cover the figs. If you're lucky enough to have an environmentally controlled greenhouse, you may not need to cover it.
• Water them monthly until just moist so the roots do not dry out completely. Do not overwater.
• Figs require a minimum of 100 hours of chilling in order to produce fruit. So you do not want to keep them toasty. You want them to remain dormant until spring. Bring outdoors in April.
• Unless your container fig is very large, do not prune or fertilize until spring.

My containered figs were in a very cold, uninsulated garage, so I put straw bales around the pots for added insulation. I have one 'Mission' fig in a 3-by-3-foot pot that I do not move but protect as if it were in-ground (see below).

In-Ground Figs: Two Protection Methods

Before planting a fig tree in the ground, think about planting it in the most protected areas of your yard to insulate your fig from extreme cold and drying winds, such as next to a southern-facing wall.

1. Prepare, Wrap, and Cover

• As with figs in containers, after a hard frost, remove all remaining leaves and unripe figs.
• Protect the base of the plant by mulching 6-12 inches with leaves, straw, or other organic materials
• Prune back the branches to a manageable height. This will encourage new growth in the spring.
• Tie or bungee the branches. They are very flexible and bendable.
• Cover them with burlap, canvas, row cover, a quilt, or other available breathable wrapping (not plastic) to protect from the wind.
• Encase the whole tree in cardboard.
• Fill loosely with straw or other dry, undiseased materials to leave air space.
• Then, tarp to keep moisture out, leaving room at the bottom for air to circulate.
• You could also place an upturned bucket or a planting pot on top of the wrapping materials.

Cautionary Tales: In the past, I have used bubble wrap or even pipe insulation. Both of these created moist environments and led to fungal diseases such as powdery mildew. I imagine that any kind of wrapping (like plastic) that prevents air circulation or water evaporation would encourage disease. Straw (not hay) used as insulating fill is generally sterile and provides air pockets. I have also used leaves as fill around the branches, but many leaves have pre-existing bacterial or fungal issues that could have affected the branches. One year, I had a fig rust infestation that dropped almost half of my leaves in mid-August, so your choice of insulating materials may be one key to success.

2. Trench or Bury

Italian immigrants who brought their fig trees to the United States developed the practice of trenching or burying them to protect them. First, you must consider your spatial requirements for this time-consuming yet highly effective method of winter protection.

• Prune the branches to a manageable height.
• Bind these flexible branches with twine, rope, or bungees.
• Dig a trench out from the tree to accommodate its length, width, and depth, and save this soil nearby.
•  Cut down about a foot deep around the root ball so the tree can be bent into the trench while remaining mostly rooted. Yes, you will be cutting or breaking some roots. But if you keep the central, largest roots intact, the tree won't be significantly harmed.
• Backfill the removed soil into the trench.
• Put plywood, cardboard, or several thicknesses of paper on top before mulching to keep out mice, voles, or other critters that could damage the branches.
• Finally, mulch heavily with soil, straw, and/or other organic material to a depth of one foot.