Growing citrus trees like lemons, limes, and oranges can be a deeply rewarding experience, especially when you’re able to harvest your own fresh fruit. However, for growers living in regions where winter temperatures drop below freezing, protecting these subtropical plants during the colder months is essential. Overwintering citrus trees properly not only ensures their survival but also sets them up for healthy growth and fruiting in the next season. Whether you’re growing in containers or in the ground, there are key steps you can take to keep your citrus trees thriving through the winter.
Understanding Citrus Tree Cold Tolerance
Before diving into the how-tos of overwintering, it’s important to understand just how much cold your citrus trees can handle. Generally speaking, citrus trees are sensitive to freezing temperatures, with lemons and limes being the most vulnerable, and some orange varieties showing slightly more cold resistance. When temperatures dip below 32°F (0°C), damage can begin to occur especially if the exposure is prolonged. Young trees and those not yet well-established are even more at risk.
For example, Meyer lemons may tolerate temperatures down to about 20°F (-6°C) for short periods, while Persian limes are often damaged at anything below 30°F (-1°C). Oranges, depending on the variety, might fare slightly better but are still not immune to frost damage. Knowing your specific variety’s cold threshold is the first step to developing an effective overwintering strategy.
Bringing Potted Citrus Indoors
If you’re growing your citrus trees in containers, you already have a head start when it comes to overwintering. As soon as nighttime temperatures consistently dip below 45°F (7°C), it’s time to start thinking about moving your trees indoors. The transition should be gradual to minimize stress. Start by bringing them inside at night and returning them outdoors during the day for a week or so. This allows the tree to acclimate to the lower light and different humidity levels inside your home.
Once fully indoors, place the tree near a south- or west-facing window where it will get as much natural light as possible. If natural light is insufficient, supplement with a grow light to prevent leaf drop and keep the tree active during the winter months. Avoid placing the tree near heating vents or drafty windows, as sudden temperature fluctuations can shock the plant.
Watering should also be adjusted during this period. While the tree won’t be actively growing, it will still need water. Let the top inch of soil dry out before watering again, and avoid letting the tree sit in water to prevent root rot. Occasional misting can help combat the dry indoor air, which citrus trees generally don’t appreciate.
Outdoor Overwintering Strategies
If your citrus trees are planted in the ground or are simply too large to bring indoors, you’ll need to rely on outdoor protection methods. In warmer climates where winters are mild and frost is rare, this may involve only a few precautionary steps. However, in cooler areas, more involved methods are necessary.
Start by mulching heavily around the base of the tree 2 to 4 inches of organic mulch will help insulate the roots. Next, consider wrapping the trunk and lower branches with burlap or frost cloth, especially for young trees. In extreme cold spells, you can build a simple frame around the tree using stakes and drape frost blankets or even old bedsheets over the entire structure. This creates a makeshift greenhouse effect that traps heat from the soil and protects the tree from frost damage.
If you have access to outdoor-safe heating elements, such as string lights (non-LED, as they produce more heat), you can wrap them around the tree under the frost cloth for extra warmth. Just be sure to use weatherproof cords and monitor them closely.
Reducing Stress During Dormancy
Citrus trees don’t go fully dormant like deciduous trees, but they do slow their growth considerably during winter. This semi-dormant phase is a sensitive time, and reducing stress is key to a successful overwintering. Whether indoors or out, avoid pruning during this period unless it’s to remove dead or diseased wood. Heavy pruning should wait until early spring when new growth begins.
Feeding should also be paused during the winter months. Fertilizing while the tree isn’t actively growing can do more harm than good. Resume feeding in early spring with a citrus-specific fertilizer once you see new growth beginning to emerge.
Pest control remains important, especially for indoor trees. Spider mites, scale, and aphids are common indoor pests and can quickly spread if not addressed. Inspect leaves regularly and treat infestations with neem oil or insecticidal soap as needed.
Monitoring and Preparing for Spring
As winter winds down and days begin to lengthen, start preparing your citrus tree for the transition back to active growth. For indoor trees, begin reintroducing them to the outdoors slowly much like you did in the fall. Start with a few hours a day in a shaded area and gradually increase exposure to full sun over the course of a week or two.
Check for any signs of stress, such as leaf drop or yellowing, and adjust your watering schedule accordingly. This is also a good time to refresh the top layer of soil in container plants and check for root crowding. If the tree has outgrown its pot, early spring is an ideal time to repot.
For outdoor trees, inspect protective coverings and remove them as soon as danger of frost has passed. If any branches were damaged by cold, wait until new growth begins before pruning, so you can better determine what’s still alive.
Conclusion
Overwintering citrus trees doesn’t have to be a daunting task. With a little planning and attention, you can keep your lemon, lime, and orange trees healthy and productive year after year. Whether you’re bringing them inside or protecting them outdoors, understanding your trees’ specific needs is the key to success. As spring returns, your well-cared-for citrus trees will reward you with fresh blossoms, vibrant foliage, and eventually, homegrown fruit that makes all your efforts worthwhile.
