You overwinter a lime tree one of two ways. If it grows in a pot, you move it indoors before the first frost. If it grows in the ground, you wrap it in cloth and mulch the roots. Overwintering lime trees comes down to that one choice. Limes take cold damage near freezing, sooner than almost any other backyard citrus you can grow.
The forecast called for a hard frost by dawn. I checked the dolly, tipped my 15-gallon Bearss lime onto it, and rolled the pot off the south-facing patio toward the garage. The car was already parked inside. So I turned the pot sideways and walked it past the bumper into the bright corner by the window. The whole move took ten minutes. That window matters more than the muscle, because a few hours below 30°F (minus 1°C) can scorch new growth on your tree.
Your variety sets the stakes. Key lime is the tender one, and your tree starts taking damage at 30 to 32°F (minus 1 to 0°C). A Persian or Bearss lime is tougher and shrugs off air down toward 24°F (minus 4°C) before it suffers real harm. Know which tree you own before the cold rolls in. That one fact decides how early you act and how hard you work on your lime tree frost protection.
Once your potted lime is inside, give it light and a cool, steady room. Aim for 55 to 65°F (13 to 18°C) by a bright south or west window. Skip the spot next to a heat vent, since dry forced air drops leaves fast. Cut back on your watering too, because the tree slows down in winter and soggy roots rot. When you bring lime tree inside for the season, treat it like a resting plant, not a growing one, and you will see it sail through to spring.
Plan to act before the first frost, since limes are the most cold-sensitive common citrus and damage starts near freezing.
Bring container limes into a bright spot at 55 to 65 degrees Fahrenheit (13 to 18 degrees Celsius), such as a sunny window or cool garage with light.
Wrap the canopy in frost cloth, mound mulch over the root zone, and water bare soil before a freeze to help it store heat.
In spring, reintroduce the tree gradually over a week or two so it acclimatizes to brighter light and warmer air without shock.
A tree planted in the ground stays put, so you protect it in place. Drape frost cloth over the whole canopy and pin it to the soil to trap warmth from the earth. Pile 4 to 6 inches (10 to 15 cm) of mulch over the root zone to guard the roots. Then water the bare, open soil a day before a freeze, since wet ground holds heat and gives off a few extra degrees overnight. Old-style holiday string lights under the cloth add a gentle boost on your worst nights. Pull the cloth back each morning once the sun is up so the tree can breathe.
Keep in mind that a pot has no ground around it to buffer the cold. A container lime acts like one hardiness zone colder than the same tree in the soil, so move it indoors earlier than you think you need to. Watch the clock as much as the thermometer, because a long freeze does more harm than a short dip. Two hours at 28°F (minus 2°C) is survivable. A whole night at that mark is not. Smart overwintering lime trees comes down to acting early. Good winter citrus care means you read the length of the cold, not just its low number.
Read the full article: Lime Tree Care: A Complete Growing Guide
