How to Grow an Avocado Tree Indoors

Growing avocado trees outdoors as productive fruit trees can be tricky, but growing them as houseplants is easy, resulting in a fast-growing seedling that will reach up to 30" a year with glossy, oval leaves 4 to 8 inches long with shades of dark-green and lighter-green. The tree could eventually stand 12' tall, however, it's unlikely your tree will ever bear fruit and even if it does, the fruit from the offspring most likely won't resemble the original.

When growing as an indoor plant, it's better to purchase a dwarf avocado tree rather than trying to buy one from seed, especially if you hope that it may produce fruit someday. When grown from seed, it could take up to ten years to bear fruit, while a dwarf fruit tree (yes, avocado is a fruit!) gives you a head start. Keep in mind that all parts of the avocado plant are toxic to animals.

Can You Grow an Avocado Tree Inside?

Avocado trees can thrive inside, if they're given a bright, sunny spot to enjoy full sun. Similar to other citrus plants, they'll do well in the year-round warmth of indoors with steady humidity. However, because they grow quickly, you'll want to consider a spot where there's room to expand.

How to Grow Avocado From Seed

Just like a papaya houseplant that quickly grows from an easily accessible seed, you can use the seed of an avocado plant to propagate a new plant. The seed of an avocado is the large brown pit. Here's how to grow your avocado houseplant:

1. To sprout an avocado seed, insert three toothpicks into the seed and suspend it with the broad end down over a glass of water.
2. Cover about an inch of the seed with water.
3. Keep it in a warm place, but not in direct sunlight.
4. The seed should sprout in two to six weeks. Let the young plant grow to 6 inches, then cut it back to 3 inches to encourage stronger root growth.
5. When the roots have grown thick and the stem has new leaves again, plant in soil in a pot about 10 inches in diameter, leaving half the seed still exposed above the soil. Make sure the pot has a drainage hole.

How to Care for Avocado Trees Indoors

Caring for avocado trees is generally easy and, when avocado is grown as a houseplant, it is often grown from seed (the fruit pits) that can be sprouted in water or directly in potting soil.

Established plants will do best in sunny windows. Fertilize them regularly during the spring and summer growing season with a balanced granular fertilizer.

Avocados grown indoors are mostly novelty plants. If you want it to bear fruit and turn into the tree it really is, you'll have to move your avocado outside, but this may only work if you live in a warmer climate.

Sunlight

Like banana trees, avocado plants thrive in full sun, ideally 6 to 8 hours of direct sunlight. They will tolerate some shade, but potted indoor plants generally need the brightest spot you can find. If you're starting from a seed, the seed can be kept on a bright windowsill until roots form, and the first leaves emerge.

Artificial Light

Avocado trees require direct sunlight to grow properly and, eventually, produce fruit. Because the sunlight is less direct indoors and not sufficient for a tropical plant indoors, it's necessary to supplement it with an artificial grow light if you hope to see fruit on your tree.

Temperature and Humidity

As a tropical tree, avocado plants prefer warm growing seasons, but can take winter temperatures down to 50 degrees Fahrenheit, when growth will slow. They prefer a consistent 50% humidity.

Watering

Give the plant water when the soil is dry to the touch. Avocado plants should be kept continuously moist, but never soggy, and adequate drainage is essential. Watch for leaf yellowing, which is a sign of too much water.

Air Circulation

Because avocado trees need cool nights to product fruit, consider adding a fan near the tree for air circulation. This will mimic the cool nights that the avocado tree prefers.

Fertilizer

Indoor avocado houseplants have vastly different fertilizer needs than outdoor avocado trees. To keep your avocado houseplant's deep green leaves, fertilize it with a small amount of water-soluble food weekly to monthly during the growing season.

Pruning and Maintenance

The first serious trimming should occur when the plant is only 12 inches tall. At that time, cut it back to 6 inches and allow for new leaves and stems to form.

As it gets taller, pinch off new growth throughout the summer to force new branches to form, because avocado fruit develops on new growth. Keeping the new growth pinched off will also keep the plant bushy while controlling its size.

Pollination

Avocado trees are able to self-pollinate, which means that two trees are not necessary for fruit to grow. But, if you have just one tree indoors, it could be helpful to shake the tree a bit to release the pollen.

Container and Size

When you first purchase an avocado tree, look for a 6" to 8" pot with drainage holes and a depth twice as deep as the roots. Ideally, terracotta is the best material since it is porous and allows water to drain easily so that the soil doesn't become soggy. Every year, you will need to trade up in size to accommodate the growing avocado tree.

Potting Soil and Drainage

A rich, fast-draining potting soil mix is ideal. Look for a mix with sand, loam, and peat moss, in addition to limestone, perlite, and crushed granite.

Potting and Repotting Avocado Plants

Repot your avocado every spring when the plant begins to grow again. For the first few years, trimming your avocado is necessary to encourage a bushy plant. You can place the avocado outside during summer, and bring it inside before the first frost.

Types of Avocado Plants

Although there are about 1,000 varieties of avocado, the one most likely to find its way into your home is the Haas avocado, which is grown in tremendous quantities in California and throughout Latin America. These are small, pebbly avocados with high-fat content and delicious flesh. Larger, lighter green Florida avocados are also found in season. You'll find plenty of healthy pits inside any of these types of avocados that you can use to grow your plants.

Propagating Avocado Plants

Avocado plants can be propagated in a number of ways., but it is usually done for avocado trees planted in the landscape. Professionals graft desirable avocado varieties onto disease-resistant root-stock to produce a healthy tree with the desired kind of fruit or preferred size.

They can also be propagated by air-layering: encouraging roots to grow by scarring a tree branch, wrapping the wounded area with a small amount of rooting medium, and allowing a bundle of roots to develop while the branch is still on the tree. Once a network of roots is developed, the branch is snipped off and planted in soil.

Common Growing Problems

If your avocado tree's leaves begin to turn brown, there could be a few reasons. It could that the tree is not getting enough water. In that case, make sure to water the tree every time the soil dries. You want to keep it consistently moist. It could also be that the tree is too cold or being exposed to drafts or that it is not getting enough humidity. Avocado trees do not do well in temperatures below 50 degrees Fahrenheit.

Common Pests & Plant Diseases

Look for symptoms like leaf yellowing, which can indicate too much water or sluggish drainage. They may develop root rot in overly wet potting soil.

When grown outdoors, avocado trees are threatened by laurel wilt, caused by the Raffaelea lauricola fungus. It is transmitted by several different species of ambrosia beetle. Infected trees usually succumb within 4 to 8 weeks.

Common Problems With Avocado

The most common problem with the otherwise easy-to-grow avocado houseplant is excess salt in the soil. Keep an eye out for a white crust on the soil, which means there's an excess of salt build-up from the fertilizer. Flush the pot regularly.

Moving Avocado Trees Outdoors for the Summer

Once the temperatures have creeped up for the summer and are consistently above 50 degrees Fahrenheit, you can take the warm weather-loving avocado tree outside for the season But there are a few things to consider first.

Considerations

Young avocado trees may not be able to handle all-day direct sun, so make sure they are in a spot where they will get partial shade. Once the tree is established, then it can be moved to full sun, where it has the best chance of successfully producing fruit.

When to Bring Avocado Trees Back Inside

Bring your plants inside if it's going to be below 50 degrees Fahrenheit. Winter's lack of humidity may cause your plant to lose leaves, but they will come back when the weather is warm.