How to Grow Avocado

The avocado tree – a plant that produces smooth, creamy, and nutritious fruits essential in dishes like guacamole – can be grown from the seed left after eating the fruit. Although an avocado tree grown from seed takes longer to bear fruit (it can take between 7 to 15 years), this is a rewarding hobby as you will have a lovely avocado tree to admire while you wait. Once the tree is strong, you can either wait for it to grow or speed up the growth process by grafting a branch from a high-yield tree onto your own. Regardless of the method, you can grow your own avocado tree by following the steps below!

Find a warm spot with partial sunlight. Avocado trees love the sun, as they are subtropical plants. Native to Central America, Mexico, and the West Indies, avocado trees thrive in hot, humid environments. Although avocados have been cultivated in distant regions like California, they still require plenty of sunlight to grow well. However, there is a paradox: young avocado trees can suffer from too much direct sunlight (especially before they develop large leaves). Therefore, if you're planting an avocado from seed, choose a location where it will receive some sunlight during the day but not continuous sunlight.

• A sunny windowsill is an ideal place for growing an avocado tree. In addition to partial sunlight, windowsills allow you to control the temperature and humidity around the plant.

Avoid cold, wind, and frost. Typically, avocado trees do not thrive in harsh weather conditions. Snow, cold winds, and sudden temperature drops, which can harm even more resilient plants, can be fatal to avocado trees. If you live in a tropical or subtropical climate with mild winters, you can grow your avocado tree outdoors year-round. However, if your area experiences winter temperatures below freezing, you will need to move your mature tree indoors during the winter to protect it.

• Different avocado varieties have varying cold tolerance. Below are some common avocado types and the temperatures at which they are likely to suffer frost damage:
• West Indian — 28-29^o F (-2.2-1.7^o C)
• Guatemalan — 27-29^o F (-2.8-1.7^o C)
• Hass — 25-29^o F (-3.9-1.7^o C)
• Mexican — 21-27^o F (-6.1-2.8^o C)

Choose fertile, well-draining soil. Like many other garden plants, avocado trees grow best in loose, nutrient-rich soil. This type of soil not only provides the necessary nutrients for healthy avocado tree growth but also reduces the risk of waterlogging and improves aeration. For the best results, prepare the soil (such as nutrient-rich, organic compost) when your avocado tree has established roots and shoots.

• You don't need to prepare the planting soil right from the start, as the avocado seed will be grown in water before being planted in the soil.

Choose soil with a relatively low pH. Similar to many other popular plants, avocado trees grow best in soil with low pH (in other words, more acidic than alkaline). For optimal growth, aim for soil with a pH between 5 and 7. At higher pH levels, the tree's ability to absorb essential nutrients like iron and zinc may be significantly reduced, which can hinder the tree's growth.

• If the soil's pH is too high, you can lower it by applying organic fertilizer or planting alkaline-tolerant plants in the garden. Chemicals such as aluminum sulfate or sulfur can also be effective for adjusting the soil's pH. For more tips, check out how to lower soil pH.

Remove the avocado pit and clean it. Extracting the pit from a ripe avocado is simple. Use a knife to slice vertically around the avocado on both sides, then twist the halves apart. Gently remove the seed from one half. Finally, wash off any remaining avocado flesh from the seed until it's clean and smooth.

• Don’t discard the avocado flesh — try making guacamole, spreading it on toast, or enjoy it as a tasty, healthy snack.

Suspended the avocado seed in water. Don't plant the seed directly into the soil — you need to start germinating it in water until the roots and shoots are strong enough to support the plant. A simple way to suspend the seed is by inserting 3 toothpicks around it and placing it on top of a cup or bowl of water. Don’t worry — the seed won’t be harmed. Add enough water to submerge the bottom part of the seed.

• Make sure the seed is oriented correctly. The top of the seed is more rounded or pointed (like the top of an egg), while the bottom, which should be submerged in water, is slightly flatter and may have a different color.

Place the seed cup by a sunny window and change the water regularly. Next, place the water cup with the seed in a spot where it gets occasional sunlight (but not direct sunlight), such as on a windowsill that only receives a few hours of sunlight each day. Change the water weekly to keep it clean, and refill with water if the level drops below the bottom of the seed. Within a few weeks to a month and a half, you should see roots growing at the bottom of the seed and a small shoot emerging from the top.

• The initial stage of slow growth might take around 2-6 weeks. Your avocado seed may seem dormant at first, but be patient — eventually, roots will begin to grow and a shoot will appear.

Trim the stem when it reaches about 15 cm in height. As the roots and stem start to grow, continue monitoring the plant and change the water as needed. When the stem reaches approximately 15 cm, trim it back to around 8 cm. Within a few weeks, the plant will grow additional roots, and the stem will become thicker and fuller.

Plant the avocado seed in soil. A few weeks after the first pruning, once the roots are thicker and new leaves have grown from the stem, you can finally transplant the tree into a pot. Remove the toothpicks and place the roots into soil that's rich in organic matter and drains well. For the best results, use a pot with a diameter of about 25-30 cm. Smaller pots may cause the roots to become cramped, restricting growth if you don’t repot the plant.

• Do not bury the entire seed in the soil — only cover the roots and leave the top half of the seed above the soil surface.

Water the plant regularly. Right after planting the avocado tree into its pot, water it thoroughly. Water the soil gently until it is fully saturated. From now on, only water enough to keep the soil slightly moist, not soaked.

Help the avocado tree become sturdier. Each time you take the tree outside, it will gradually become accustomed to the outdoor conditions. Start by placing the pot in an area with indirect sunlight most of the time. Slowly move the tree to a brighter spot. Eventually, your avocado tree will be ready to enjoy direct, continuous sunlight.

Pinch off leaves every time the tree grows an additional 15 cm. After planting the tree in the soil, continue to water and expose it to sunlight. Use a ruler to monitor the tree's growth regularly. Once the stem reaches around 30 cm, pinch off all new leaves growing at the tips of the branches, leaving the remaining leaves intact. As the tree continues to grow, you should pinch off the newest leaves on the highest point every time it grows another 15 cm.

• This will encourage the tree to sprout more branches, growing into a lush and healthy avocado tree in the long run. Don’t worry about harming the plant — avocado trees are strong enough to recover from pruning without any issues.

Plant the seedling when it reaches around 60 – 90 cm. As mentioned earlier, an avocado tree grown from a seed may not develop as expected. Some trees may bear fruit in a few years, while others may take much longer or even never bear fruit. To shorten the waiting time and ensure the tree will bear fruit, you can use a professional gardening technique — grafting. For grafting, you'll need a fruit-bearing avocado tree and a seedling that's at least 60-75 cm tall.

• If possible, choose a tree with a strong, disease-resistant branch that also produces high-quality fruit. A successful grafting technique will combine the best qualities of both trees, so it's important to select the healthiest plants to avoid future problems.

Start in the spring. The best time for grafting is when the tree is actively growing, and before the weather gets too dry. Begin the grafting process in spring, and prepare for the procedure over a period of about four weeks.

Make a T-shaped incision on the seedling. Use a sharp knife to make a T-shaped cut about 20-30 cm above the ground on the seedling’s trunk. Cut horizontally about 1/3 of the trunk’s diameter, then turn the knife to make a vertical cut downwards about 2.5 cm. Gently separate the bark from the trunk.

• Be sure not to cut too deeply into the trunk. The goal is to 'open' the bark along the trunk to allow for grafting, not to harm the tree.

Cut a scion for grafting. The next step is to select a scion from the fruit-bearing tree you've chosen. Cut the scion at a diagonal, leaving about 1.2 cm below the bud and 2.5 cm beneath it. If the scion is from the middle of the branch rather than the tip, cut from above to harvest the scion.

Insert the scion into the seedling. Next, insert the freshly cut scion into the T-shaped incision on the seedling’s trunk. Make sure the green tissue beneath the bark of both the scion and the seedling are in contact — this is essential for successful grafting. Once the scion is securely placed in the incision, you can tie it in place using rubber bands or special grafting ties that are available in most garden stores.

Wait for the scion to take. If the grafting process is successful, the scion and seedling will gradually fuse together, forming a single tree. This process usually takes about one month after grafting. Once the tree has fully healed, you can remove the rubber bands. If you wish, you can carefully trim the main trunk above the new scion by about 2.5 to 5 cm to encourage the new scion to become the 'main' branch.

• Remember that avocado trees grown from seeds can take anywhere from 5 to 13 years to bloom and bear fruit.

Water regularly, but avoid over-watering. Compared to other garden plants, avocado trees require more water. However, be mindful that over-watering is a common issue for almost all plants, including avocados. Avoid frequent watering or watering too much, as it can cause the soil to become too soggy. Use well-draining soil (nutrient-rich soil is often ideal). If the tree is potted, ensure the pot has drainage holes to allow excess water to escape. Follow these simple tips, and your avocado tree will avoid the risk of waterlogging.

• If the leaves turn yellow and you're over-watering, it could be a sign that the tree is getting too much water. Stop watering immediately and only resume once the soil is dry.

Occasionally fertilize the tree. Avocado trees can grow healthy without fertilizer, but when applied properly, fertilizer can significantly boost growth, especially for young trees. Once the tree matures, you can add balanced fertilizer to the soil during the growing season according to the instructions on the package. Don't over-fertilize — it's better to be cautious when using commercial fertilizers. Always water after fertilizing to help the nutrients penetrate the soil and reach the tree's roots.

• As with most plants, avoid fertilizing young avocado trees as they are highly sensitive to fertilizer, which can burn them. It's recommended to wait at least a year before fertilizing.

Be aware of salt buildup in the soil. Avocado trees are more susceptible to salt accumulation compared to other plants. Trees affected by high salt levels can show signs of wilting, with leaf tips turning brown and burned. To reduce soil salinity, change your watering technique. At least once a month, water the tree deeply to flush out salts from the soil. The excess water will carry the salts down into the deeper soil layers, below the root zone, where they are less harmful to the tree.

• Container plants are particularly prone to salt buildup. Once a month, place the pot in a sink or take it outside to allow water to run through the pot and drain from the bottom.

Know how to handle diseases and pests affecting avocado trees. Like any other plant, avocado trees can suffer from diseases or pests that threaten fruit quality and even jeopardize the tree's health. Identifying and addressing these issues is essential for maintaining a healthy avocado tree that produces good fruit. Here are some common pests and diseases affecting avocado trees — for further information, you can refer to the following source:

• Root rot — Deep, sunken lesions and rust-like patches on the tree may leak sap. Trim away affected parts. Root rot can eventually kill the tree, even when all other growing conditions are ideal. Stop watering immediately, and if the situation is severe, dig up the roots to expose them to air. This disease sometimes causes the tree to die.
• Wilt and dieback — Dead patches on the tree. Leaves and fruits in these areas wither and die. Remove affected areas immediately and sanitize your tools before reuse.
• Leaf borers — These pests create yellow spots on the leaves and quickly dry them out. Damaged leaves may fall off. Use commercial insecticides or natural pest control methods like pyrethrin.
• Stem borers — Small holes in the tree may leak sap. Preventative measures are best — healthy, well-nourished trees are less vulnerable to pest infestation. If the tree is infected, prune the affected branches to prevent spreading.

• There are specialized fertilizers designed for avocado trees. When used correctly, these products are almost always effective. Other fertilizers can also be beneficial, especially if the soil isn't ideal for the tree. Since you'll be consuming the tree's fruit, consider opting for organic fertilizer instead of synthetic ones.

• While you can grow an avocado tree from a seed, keep in mind that trees grown from seeds can be quite different from the parent tree and may take 7 to 15 years to bear fruit. The fruit from a seed-grown avocado tree may have a different flavor compared to the parent tree's fruit.
• If the tree's leaves turn brown with tips scorched, it could indicate excessive salt buildup in the soil. Allow water to flow through the pot and drain out for a few minutes to help alleviate this.

• Avocado seed
• Container for seedling germination
• Toothpicks
• Pot for transplanting the sprouted seedling
• Fertilizer
• Knife
• Rubber bands/tape for grafting the tree
• Organic pesticide (optional)