Citrus fruits are often associated with tropical or subtropical growing regions, off-limits to growers in cooler areas. This makes perfect sense since citrus trees require some warmth and humidity, but it’s disappointing to citrus-loving gardeners who live too far north. So can you grow lemon trees in zone 6?
Lemon and other citrus trees are best suited to USDA zones 9 or higher. However, if you live in zone 6, or another zone with warm summers, you may want to consider growing lemon trees in containers. Many lemon varieties will thrive in containers that can be moved indoors for winter.
Zone 6 Location and Characteristics
The U.S. Department of Agriculture uses the lowest average winter temperatures to divide the U.S. into 13 plant hardiness zones. These zones help gardeners determine which plants are best suited to their local climates.
Zone 6 comprises any region whose lowest average temperatures fall between -10℉ and 0℉. Zone 6 represents a large portion of the United States: there are places as far north as Washington, as far south as New Mexico, and stretching from coast to coast that fall into zone 6.
There are several interactive features on the USDA Plant Hardiness Zone Map that make it easy for you to determine which zone you live in. It may be best to search by ZIP code because zones can vary even within a single county.
It’s important to remember that winter temperatures are the only factor that determines the boundaries between zones. Soil type, rainfall, wind, and summer temperatures will differ throughout zone 6.
How to Grow Lemons in Zone 6
Lemons are extremely cold-sensitive evergreens that can sustain damage at any temperature below freezing. The most severe damage happens when winter temperatures hit 20℉; this is the temperature at which the tree’s wood will become damaged, which puts the tree in danger of collapse or death (source).
Given this cold sensitivity, it’s easy to see why lemon trees would not be successful in zone 6 if they were planted directly into the ground. This is why container gardening is your only option if you live in zone 6 and want to grow lemons. Fortunately, with the right equipment and right lemon cultivar, you can enjoy many successful harvests.
Choosing a container for your lemon tree is one of the most important growing decisions you will make. In fact, depending on the type of tree and how old it is when you buy it, you may want to plan on repotting it every three to five years.
Regardless of whether you buy one pot or several over the course of your tree’s life, there are several factors to consider:
- Available space
Because of their trees’ temperature needs, many lemon growers keep their trees outside during warm months and move them indoors for winter. This means that their containers must be fairly easy to move.
Large containers filled with soil and a tree can be extremely heavy. When your tree is young, it may be easy enough to simply carry the pot from one place to another. As your tree matures, however, this will likely not be a safe option.
Some gardeners solve this problem by placing their lemon tree’s container on a plant caddy, dolly, or other wheeled device. Others find it easier to attach wheels or casters to the bottom of the pot itself.
When you first buy your lemon tree, it should be transplanted into a pot that is at least two inches wider than the container it comes in.
Some lemon cultivars will become quite large, even in pots, and the largest ones will eventually need containers that are up to 36 inches in diameter. Before you purchase a container, make sure it’s a size that will be suitable for the type of tree you want to grow.
Lemon trees require approximately six hours of direct sunlight each day to produce blossoms and fruit. Since they are evergreens, their sunlight needs will not change in the winter.
This means that your tree’s container will need to fit somewhere in your home where it will be near a southern or southwestern exposure.
If your indoor space is limited, make sure to choose a container that will fit your space while still allowing enough room for the tree’s roots. This may also mean choosing a lemon cultivar that will stay relatively small even when it’s mature.
Because they aren’t too heavy, plastic containers and decorative pots are good options for lemon trees.
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Other options, such as wood, clay, or metal, may work as well, but they tend to be heavier. Keep your mobility needs in mind–the heavier the pot, the harder it will be to move. Again, having a caddy or dolly on hand will improve your container’s mobility and expand your choices.
Regardless of the material you choose, make sure that your pot has holes in the bottom for drainage.
Native soil is not recommended because of its heaviness. Instead, you should buy a potting mix or cactus mix that will drain well. You can also make your own mix.
If you make your own, try mixing shredded aged pine bark and peat moss. Aim for a 4:1 ratio of bark to moss (source).
Some of the most common lemon varieties are too large for container growth, so be sure to look for a dwarf cultivar. The following are some of the easiest varieties to grow indoors:
- Citron (Citrus medica), which produces sweet fruit with thick, bumpy rinds.
- “Eureka” (Citrus limon), which is thornless and produces full-sized fruit.
- “Meyer” (Citrus limon), which is actually a hybrid of lemon and orange whose fruit is very juicy and sweet. Make sure your Meyer is the improved, virus-free hybrid.
You can also grow a lemon tree from seed. Lemon trees grown from seed are unlikely to ever produce flowers or fruit, but they are still attractive ornamentals.
Care and Maintenance
Temperature and Sunlight
The ideal growing temperature for lemon trees is between 55℉ and 85℉.
When outdoor temperatures are regularly 50℉ or higher–day and night–you can move your lemon tree outside. They will need a week or two in partial shade to acclimate to the change in environment. Before nighttime temperatures dip below 50℉, move your tree inside.
Lemon trees need abundant sunshine, at least six hours per day, in order to produce blooms and fruit. Their growth will slow down a bit in the winter, but even then, they need about six hours of direct sunlight per day. You may find it necessary to supplement with a grow lamp during the months your tree is indoors.
The amount of water you give your tree will vary by the size of your container, the size of your tree, and the season. In general, however, it is best to give your tree enough water for the soil to stay moist but not spongy.
Instead of giving your tree a little water every day, plan to water deeply, allowing the top inch or two of soil to dry out before watering again. Lemon trees are susceptible to root rot, so it’s important to avoid overwatering.
In the winter, you can decrease the amount of water you give your tree, since its growth will slow down at that time.
Inconsistent watering is one of the common causes of a tree dropping lemons.
Lemon trees need regular fertilization, as they are heavy feeders. Look for fertilizers labeled “citrus/avocado,” “acid-loving,” or simply 2-1-1. Slow-release granules will work best, but you can also dilute a water-soluble quick-release fertilizer if your tree’s nutrient needs are urgent (source).
Lemon trees are self-fruitful, which means they don’t require another lemon tree for cross-pollination. However, in order to produce fruit, they need insects to carry pollen from flower to flower.
If your tree blooms indoors, you will need to assist with the pollination process. Once your tree’s flowers open, take a soft paintbrush and very gently brush the flowers, making sure to brush some pollen into the flowers’ centers.
During the warmer months, protect pollinating insects by not using broad-spectrum insecticides that will reduce their populations.
See our complete guide to the best companion plants for lemon trees which fully explains how to attract pollinators and repel pests!
It’s amazing to think that exotic, tropical fruit can be grown inside your own home, and even more amazing that it can be done so easily! If you live in zone 6, or any other zone that isn’t naturally hospitable to lemon trees, try growing a dwarf variety in a container. With the proper care and maintenance, you can enjoy many delicious harvests.