Choosing Citrus Varieties for Hot-Zone Climates

Citrus trees have varying levels of frost tolerance, so it's important to choose the type of citrus tree best suited to your climate. All citrus trees are frost-tender and are likely to be damaged by freezing temperatures. Because of this, citrus trees are usually grown in hardiness zones 9-11. Some colder zones can push the boundaries of growing citrus by planting the most frost-tolerant varieties and/or growing citrus in containers that can be moved to a sheltered location during the coldest times of the year.

Even within zones 9-11, it is important to remember that each locale and even parts of your yard may have areas where it is too cold to grow citrus well.

If cold weather is a concern, remember that cold air flows to low areas in the landscape such as the base of mountains or a hill. Low areas in the landscape have cooler temperatures than surrounding areas. Choose a sunny location on the south or east side of the yard with shelter from the northern wind. In addition, planting a tree next to a wall that receives sun in the winter may protect the tree in cold weather.

That being said, it is a good idea to protect citrus trees during freezing temperatures no matter where they are planted in your yard. If freezing temperatures are expected, water all citrus trees deeply no matter their age. Moist soil helps retain the heat in the soil. During frost events, cover citrus trees with frost cloth or burlap, being careful to completely drape the tree from the top all the way to the ground to trap radiating heat from the ground. If extra frost protection is desired for young trees, wrap trunks with cloth or burlap until the danger of frost is past in the spring.

Knowing when citrus is ready to harvest also influences the decision of which type of citrus tree to plant, especially if you have more than one variety of citrus tree. Staggering harvest times helps ensure less waste of the tasty home-grown fruit. Choose varieties of the same type of citrus that ripen at different times to extend your harvest season.

Some types of citrus have a harvesting window as little as 2 months, while others remain ripe on the tree for several months. Harvest fruit anytime during the harvesting window for each type of citrus.

Rind color does not always indicate ripeness. The color of citrus is affected by the weather, not necessarily the ripeness of the fruit. The best way to tell if citrus is ready to eat is to try one or two at a time until the taste suits you. The longer citrus fruit remains on the tree, the sweeter it becomes. As the fruit ripens, the acid content goes down and the sugar content goes up. Once picked, the fruit will not ripen anymore. Once unpicked fruit is past its prime, it may become soft, harden on the vine, or drop.

Exact months for ripening varies depending on your location. (Arizona dates differ slightly from California and Florida, etc.) But they follow a similar pattern with lemons and limes ripening first.