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How to Grow and Care for an Indoor Lemon Tree

lemon and flower

With sweet-smelling flowers, glossy foliage and tart, tasty fruit, an indoor lemon tree rewards your attention year-round. Regardless of your climate, you can grow a container lemon tree indoors and enjoy your own homegrown lemons. Growing indoor lemons isn't hard as long as you choose the right tree and meet its special needs. These basics on how to grow and care for an indoor lemon tree can have you drinking lemonade in no time.

When grown outdoors in warm climates, regular lemon trees grow 20 feet tall and take up to six years to bear fruit.1 For indoor lemons, you need a tree that stays small and delivers lemons sooner. Growers graft indoor lemon tree varieties onto special dwarfing roots that speed up fruit-bearing ability and keep trees small.

Some of the easiest, most popular indoor lemon trees are actually crosses with other fruits, but some are true lemon trees that do well in pots. The best dwarf indoor lemon tree varieties include:

  • Dwarf Improved Meyer – The easiest indoor lemon tree, this cross between lemon and mandarin orange offers sweet, tangy lemons.
  • Dwarf Ponderosa – Another popular indoor choice, this lemon and citron cross bears large lemony fruit.
  • Dwarf Variegated Pink Lemonade – The green-and-yellow variegated fruit on this true lemon tree has pink flesh (but clear juice).

Most dwarf lemon trees sold by nurseries are two to three years old — old enough to start bearing fruit, but still immature. Container size helps limit a tree's eventual height, but most indoor dwarf Meyer lemon trees grow to at least 3 to 4 feet tall. Other indoor varieties can grow to 6 feet or more.

If you plan to grow a lemon tree from a seed, understand that the new tree won't be the same as the one the seed came from. Starting a lemon tree from a cutting will yield the same tree — from the ground up — but the process is challenging. Either way, your new tree won't have the small size and disease resistance of grafted dwarf trees, and you won't see fruit for many years.

blooming lemon tree indoors

Lemon trees fill your home with fragrance and fruit.

It's tempting to start your lemon tree in a pot worthy of its final size, but it's better to start out small. Overly large pots with excess soil make it difficult to tell when your indoor lemon tree needs water. For most young, nursery-grown trees, start with a 12-inch diameter container. As your tree grows over the years, slowly progress to pots double that size in width and depth.

Lemon trees do well in all kinds of pots, from porous terra cotta to lightweight resin. Just make sure the container has large, unobstructed drainage holes. Like other citrus trees, lemons prefer cool roots, so avoid black pots and other dark colors that heat up in sunlight.

Always use a deep saucer under your container to protect indoor floors from excess water. Consider putting a wheeled plant dolly underneath. Lemon trees get heavy and hard to move as they grow.

Lemon tree roots demand abundant oxygen, so proper planting and excellent drainage are key. When planting your tree, the flare at the base of the trunk should sit slightly above your eventual soil line.

Start by filling the new container's bottom with soil, then lightly tamp it down. Repeat until you reach the right depth for your tree's root ball. This helps provide a good foundation so your tree won't settle in too deeply. Always leave a few inches at the top for watering.

Indoor lemon trees do best when their soil stays evenly moist. Choose a well-draining potting mix designed for indoor palm trees or citrus. These mixes help prevent soggy soil while still retaining moisture, so roots don't get too wet or too dry.

As a final step, treat your newly planted lemon tree to Pennington UltraGreen Plant Starter with Vitamin B1, which provides micronutrients and reduces transplant shock.

lemon tree in greenhouse

Nursery-grown dwarf lemons bear fruit at a young age.

Once your lemon tree is in its new container, it's ready for its new environment. These two factors are critical to a successful indoor lemon tree:

  • Light: For peak performance — from blooms to fruit — your indoor lemon tree needs close to eight hours of sunlight each day. The more light it gets, the better your results will be. Lemons generally do well in front of unobstructed south- or southwest-facing windows. You can also add artificial light if needed.
  • Temperature: Indoor lemon trees grow best with nightly temperatures near 65 degrees Fahrenheit, which suits most homes fine. Lemon trees won't tolerate hot or cold drafts, so place them away from all air conditioning and heating ducts.

During warm summer months, consider giving your indoor lemon tree an outdoor vacation. Once all danger of spring frost passes, gradually acclimate it to the outdoors. The extra sunlight will do it good — and reward you with fruit. Before fall frost comes, move it back inside. Always move lemon trees gradually. Abrupt changes in light and temperature can make fruit drop.

To keep your lemon tree healthy, allow the soil to dry out about 3 inches deep before you water. Then water thoroughly until it runs through the pot's drainage holes. Keep the soil moist, not overly wet, but never let it dry out completely. Test soil with a moisture meter (available online and in garden centers) or use your index finger instead.

During active growth, especially if they're outdoors during summer, container lemon trees may need daily watering. During winter, water only as needed to keep soil moist. Timing varies depending on your indoor temperatures, your container and your tree size. Watch for warning signs such as yellow leaves, which signal soggy roots or nutrient problems.

To grow tasty fruit and beautiful foliage, your indoor lemon tree needs proper food. Like other citrus trees, lemon trees require plentiful nitrogen as well as other essential nutrients, including magnesium and iron.1 This is especially important for indoor lemon trees, which are restricted to containers.

A premium citrus fertilizer such as Pennington UltraGreen Citrus and Avocado Plant Food 10-5-5 provides indoor lemon trees with an ideal blend of primary nutrients and micronutrients at planting time, then it keeps feeding for up to four months.

As your tree grows older its needs will change, so follow label instructions for your indoor lemon tree's age and pot size. Feed container lemon trees every three to four months. Avoid disturbing shallow roots when you feed.

lemons

Indoor lemon trees look as good as their fruit tastes.

Unlike some fruit trees, lemons are self-pollinating. That means they don't need pollen from another lemon tree in order to bear fruit. But in nature, lemon trees rely on insects to pollinate their blossoms. Better pollination translates to more and better fruit.

With popular indoor varieties your tree should bear fruit on its own, but you can also help it along. When flowers are blooming and you stop to inhale the intoxicating fragrance, gently shake the branches to help spread pollen within the blossoms.

Indoor lemon trees typically need little to no pruning. Most indoor varieties are thornless, but some lemon trees have thorns. Wear long sleeves and gloves to prune away thorns and all shoots or roots near soil level. Most lemon trees fruit on outer branches, so wait until after fruit sets to avoid pruning away your prize.

By learning how to grow and care for a lemon tree indoors, you can enjoy a year-round parade of beautiful foliage, fragrant blossoms and shareable lemony treats. At Pennington, we're committed to bringing you premium plant fertilizers and expert advice to help you grow the indoor lemon tree of your dreams.

Always read product labels thoroughly and follow the instructions carefully.

UltraGreen is a registered trademark of Central Garden & Pet Company.

Pennington is a registered trademark of Pennington Seed, Inc.

Resources:

1. J.H. Crane, "Lemon Growing in the Florida Home Landscape," University of Florida IFAS Extension.
Pennington Fertilizer Resources