How to Grow Lemon Trees Indoors

In various cultures, lemon trees symbolize the goodness of life: love, light, and happiness, to name a few. They make wonderful holiday or housewarming gifts, or commemorative plants to celebrate special occasions. Whether buying a lemon tree for oneself or receiving one as a gift, it makes for an excellent, long-lived indoor plant offering attractive foliage, fragrant blossoms, and tangy fruit for year-round appeal.

Growing a lemon tree indoors is easy, but it does require a bit of specialized care in terms of light and fertilizer. Read on to learn how to grow a lemon tree indoors.

Indoor Lemon Tree Care at a Glance

Common Name: Lemon
Scientific Name: Citrus limon
Soil: Well-drained, pH 5.5 to 6.5
Light: Bright
Water: Medium
Food: Balanced organic or slow-release formula
Temperature and Humidity: 65 to 75 degrees Fahrenheit, 50 percent humidity
Propagation: Rooted cuttings, grafting
Safety: Thorns, allergenic for some, nontoxic to humans, somewhat toxic to pets

Lemon Tree Characteristics

The lemon tree grows in semi-tropical regions of USDA hardiness zones 9 to 11, but it can be an excellent indoor plant in cool regions as well. It’s a relatively easy-going plant that prefers to spend the summer outdoors. Lemon trees require little pruning, moderate water, and a consistent supply of nitrogen-rich plant food. Arguably, their most vital growing requirements are bright light and good air circulation.

Cool overnight temperatures help to stimulate flowering, especially in winter and early spring. Like other citrus trees, lemons produce small white fragrant flowers. They are mostly self-fertile, so a single tree can offer high fruit yields with patience. Ripening may take up to a year before the lemons are ready to harvest.

Lemon tree leaves emerge with a reddish tint and develop to deep green above and lighter below. Flowers are held singly, in pairs, or in small clusters, and the aromatic fruits are dotted with oil glands that produce a lemony scent as they ripen.

Although lemon trees can grow to 20 feet or higher when planted outdoors, they make quality specimens in containers, where they typically reach half that height. This makes them a choice gift for plant lovers. Lemon trees pruned and repotted every couple of years maintain a shrubby form around 5 to 7 feet tall.

Related: 20 Clever Household Uses for Lemons

Types of Indoor Lemon Trees

• Dwarf Improved Meyer Lemon is a cross between a citron and a mandarin that produces small, rounded yellow fruits with a semi-sweet flavor.
• Dwarf Ponderosa Lemon is a cross between a lemon and a citron that bears large, traditional lemony fruit.
• Dwarf Variegated Pink Lemon features green and yellow variegated fruit with deep pink flesh and clear juice.
• Dwarf Lisbon Lemon is a vigorous tree that produces an abundance of juicy, flavorful thin-skinned fruits.

Selecting Soil for Lemon Trees

Lemon trees grow best in rich, well-draining soil with a pH between 5.5 and 6.5. High-quality indoor-outdoor container mixes should be adequate. Apply fertilizer specifically designated as “citrus food” to help maintain the proper pH.

Potted lemon trees require both an adequately sized container and the right kind of potting mix to thrive. When repotting, incrementally increase pot sizes. For instance, a new lemon tree in a 3-gallon (10-inch diameter) pot should be transplanted to a 12-inch pot. Do not go too big all at once, or the risk of root rot increases. A 16- to 20-inch container will be the right size for a permanent home.

The Right Light

Good flower and fruit production demands full sun exposure, which ranges from difficult to impossible inside some homes. Most gardeners find success by moving lemon trees to a sunny location outdoors for the growing season and back to a bright room indoors on cold nights.

In springtime, transplant lemon trees to a bigger pot if more growing space is needed. When the danger of frost has passed, move the tree first to a bright filtered-light location outdoors. Gradually increase the duration of direct sun exposure daily over the course of 2 weeks. If cold weather is in the forecast, transition the tree back into a bright room—preferably one with large south-facing windows.

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Watering Lemon Trees

Water the plant deeply whenever the soil dries out to a depth of 2 inches. Probe the soil with a stick or quarter-inch dowel rod marked with a 2-inch depth indicator. Leave the dowel in the soil for 1 minute. Then, pull it out and look at the bottom end. If moisture is evident at the base of the dowel, don’t water the tree. If the dowel appears dry, thoroughly soak the soil and let excess water drain freely. Do not leave standing water in a saucer beneath the tree.

Fertilizing Indoor Lemon Trees

For healthy plant growth and fruiting, lemon trees benefit from consistent feeding throughout the year. Choose fertilizer specifically formulated for citrus plants to help maintain a slightly acidic pH. A balanced fertilizer, such as 8-8-8, is best.

During the spring and summer growing season, apply granular organic fertilizer every 6 to 8 weeks; or apply slow-release fertilizer once in the spring and supplement it with liquid plant food semiweekly. At the end of the growing season, apply granular organic plant food or a second application of slow-release fertilizer to supply nutrition through the winter. Don’t use liquid fertilizer in the winter.

Setting the Temperature and Humidity

An indoor lemon tree will thrive in average home climate conditions. A temperature between 65 and 75 degrees Fahrenheit and humidity around 50 percent works well for overwintering. However, use caution when transitioning the tree outdoors in spring. An acclimatized lemon tree may suffer shock from cool temperatures below 50 degrees, and it will be damaged by frost. It’s best to keep the tree indoors in spring until all danger of frost has passed and nighttime temperatures remain above 50 degrees Fahrenheit.

Summer sun and heat are no problem for potted lemon trees after a gradual transition period. At the height of summer, they can withstand high temperatures in the 90s, so long as they are consistently watered well. Watering frequency will need to increase during hot weather.

Propagating Lemon Trees

Lemonade enthusiasts often wonder how to grow a lemon tree from a seed, but that’s not how it is done. Seed-grown fruit is extremely unpredictable in quality, flavor, and even tree characteristics. Professional growers and retail nurseries mostly sell grafted lemon trees.

To save propagation time and space, and to ensure identical genetics, nurseries fuse branch cuttings from one kind of plant with root cuttings from another. Everything growing above the graft union will exhibit the desired trait, but if any shoots appear from below the graft, they should be removed and discarded.

Instead of growing a lemon tree from seed, home gardeners can grow lemon trees either from rooted cuttings or by grafting. The easiest way to propagate the fruit tree is by taking a 6- to 8-inch branch from a stem with at least four side buds and no flowers or fruit in late spring, taking care to:

• Remove leaves from the lower 4 inches of the stem
• Dip the base of the cutting in rooting hormone
• Stick the cutting into a 4-inch pot filled with premoistened potting soil
• Place the cutting in a warm, brightly lit location and keep the soil moist but not soggy

The cutting should grow roots within a month. Use this method to grow new lemon trees on their own roots or to produce rootstock of trifoliate citrus for grafting. To graft new citrus trees, this T-budding method ensures a high success rate. Those in citrus-growing regions should follow local governance to avoid the spread of diseases.

Related: 14 Symptoms of an Unhappy Houseplant (and How You Can Treat Them)

Safety Considerations

Of course, if anyone in a home has a citrus allergy, avoid growing a lemon tree indoors. The primary symptom of citrus allergy is contact dermatitis, an itchy rash similar to poison ivy. Otherwise, lemon trees are considered safe and nontoxic for humans. Essential oils found mostly in the fruits are toxic to animals, however, so those with curious pets should exercise caution.

Some lemon varieties are thorny, and others are grafted to rootstock that might send up thorny shoots. Watch out for these stickers and be sure to prune any shoots arising from below the graft union.

Potential Pests and Diseases

Lemon trees are susceptible to mealybugs, spider mites, and scale insects. These are generally avoided with favorable growing conditions such as good sun exposure, air circulation, proper fertilization, and consistent watering. If insect problems arise, treat them promptly by plucking bugs by hand or pruning away the affected area if it is small. Quarantine the tree and spray with an appropriate insecticide if necessary.

Feeding aphids may spread a fungal disease called tristeza, indicated by yellowing of foliage and rapid decline. Infected lemon trees may succumb to root rot. Always monitor for insects and treat them whenever they appear. In cool, damp conditions, the fungus Botrytis causes fuzzy gray mold-like growth to appear on stems and flowers. Keep lemon trees in a bright, sunny location and, as they mature, prune dense branches to improve air circulation.

FAQ About Indoor Lemon Tree Care

If you are considering adding a lemon tree to your houseplant collection, the following FAQ may help to clear up any lingering questions.

Q. Do lemon trees grow well in pots?

Yes, lemon trees grow well in pots. Dwarf cultivars are the easiest to keep, but even standard varieties can be kept in check with occasional repotting and root pruning.

Q. How long do indoor lemon trees live?

An indoor lemon tree can live for decades. With good care, some lemon trees can survive for 50 years or more.

Q. Where should you place a lemon tree when grown indoors?

Bright sunlight is critical for plant health. Choose a room with large south-facing windows and place the lemon tree as close to them as possible.

Q. Are lemon trees hard to grow?

Lemon trees are not difficult to grow if your home has a bright location for overwintering.

Q. How can you tell if a lemon tree is overwatered?

A lemon tree that has been consistently overwatered may develop yellow leaves and root rot. Avoid these problems by watering deeply and consistently and by removing standing water from the container’s saucer.

Q. Why are my lemon tree leaves turning yellow?

Lemon tree leaves turn yellow in response to overwatering, underwatering, lack of fertility, or cold stress. Insect damage may also lead to patchy yellow patterns on the leaves. Follow the best growing practices outlined above and be vigilant against bug infestations to avoid these issues.

Looking for more information on tropical or semi-tropical plants you can grow indoors? Check out our guides on caring for bird of paradise plants, rubber plant, and pineapple plant.