How to Plant, Grow, and Care For ‘Thai White’ Guava Trees

A long-lived tropical tree that produces delicious, nutritious fruits, guava is easy to grow and care for. Plant this guava right in the garden in warm climates, and in cooler climates, opt for a large container. Let’s look at the ‘Thai White’ variety that produces delicious fruits that are extra high in fiber and immune-boosting vitamin C. 

What Is It?

‘Thai White’ guava is a lightly sweet and refreshing fruit. Typically, it’s consumed raw and unripe, sometimes dipped in chili, salt, sugar, or a combination of all three. 

It’s a tough small tree that makes an attractive addition to the landscape, though it won’t grow in the ground outside of zones 9-11. Outside this climate, it makes a nice container or patio plant. 

Guavas were in cultivation as many as 5,000 years ago in Peru. Spanish and Portuguese explorers imported the species to Florida and Europe. Eventually, they traveled across the continent with their delicious discovery, distributing it to Asia and India. 

Legend follows that the fruits of the guava tree were once inedible. A young boy, wanting to feed a hungry beggar, prayed for the gods to make the fruit edible. The gods obliged the boy, impressed with his kindness and compassion, giving the fruit a sweet, tangy, tart flavor we now love. 

Characteristics

‘Thai White’ is a mid-sized, evergreen fruit tree that will grow to about 15′-20′ left to its own devices. You can prune it to keep it to a more manageable size, making it easier to harvest the round, green fruits. 

The fruit is green with white flesh and has higher sugar, vitamin C, and fiber content than a pink guava. It also tends to have more seeds, lending to its more fibrous texture. The entire fruit, including the peel, is edible. 

According to the National Library of Medicine, the fruit, eaten with the peel is, very healthy. It can lower blood glucose levels and triglycerides, making it a great addition to a healthy diet. 

The plant is attractive and fits well into a tropical landscape. It usually has one or two central trunks and a many-branched, umbrella-like canopy. The leaves are broad, medium green, and have prominent veining. 

Native Area

Guavas are native to Central and South America and the Caribbean. Portuguese travelers brought the white guava to Asia in the 17th century, where it became a popular fruit to grow and eat. The Thai people refer to the fruit as farang, which denotes a foreign person of white race.

Planting

Spring and early summer are the best times to plant your ‘Thai White’ guava. The plant is in an active growth phase at this time and will establish quickly. If you want to grow it in a container, it’s fine to re-pot it any time of year. It will need to come indoors when the temperature drops below freezing. 

The roots of the guava can be extensive, growing beyond the drop line. For this reason, plant it a fair distance away from your home, structures, or concrete slabs. 

Growing from Seed

‘Thai White’ trees are often grafted and will not breed true from seed, but you can propagate this way as a fun experiment. However, it will take six to eight years to bear fruit from seed, so it’s not the most common propagation method. 

How to Grow

These trees are fast growers and not difficult to care for. They are easy to care for, and a mature tree can produce several dozen pounds of fruit. Grown from seed, it takes about eight years to mature. A ‘Thai White’ guava propagated from a cutting will bear fruit considerably sooner. 

Light

Sun, sun, and more sun will ensure plenty of delicious fruit. This variety needs a minimum of six hours of exposure, daily, but eight to ten is ideal. 

‘Thai White’ guavas can technically grow in partial shade, but the results will be sub-par. Expect a tree in partial shade to produce fewer flowers and thus fewer fruits. 

If you are growing this plant in a container, place the pot in the sunniest spot you have available. It will grow indoors with ample sunlight, but it’s best to grow it outdoors during the warmer months. Bring it in only when the temperature drops, and give it your brightest window. 

Water

Your newly planted sapling will need a lot of watering during its first season. Water every other day for the first week to encourage rooting. After this, water twice weekly throughout the growing season. Deep rooting comes from deep watering, so be sure to give it a long drink when you water. 

Allow the soil to dry between waterings so that you don’t risk fungal issues. Once established, this plant will be moderately drought tolerant. However, when there are periods of drought, you will need to water. A dry plant will show distress with wilted leaves. 

Be careful not to overwater, as this can cause root rot. Yellowing leaves and a musty smell are both signs of a plant that is being overwatered. 

If you neglect to water during times of drought, your guava may go dormant. It won’t grow as vigorously, if at all. The fruits will set and mature slowly but won’t reach their full potential. A young tree will be more affected by drought than a mature one.  

Soil

Guavas aren’t picky about soil type. They can thrive in sandy, loamy, rocky, and muck-type soils. As long as the drainage is good, this plant will be happy. 

More important than the soil type is the soil pH. This species needs a lot of iron. The iron breaks down into a more available state in acidic soil. I pH of 4.5-7 is ideal. In less acidic soil, you’ll want to give your guava supplemental chelated iron. 

These plants have shallow root systems, particularly if you propagate by air layering. To send those roots deeper, make sure to plant in loose soil, and water deeply. 

Temperature and Humidity

This tropical evergreen grows best in warm weather. When the temperature drops below 60°F (16°C), growth will slow and the tree may go dormant. Young trees are more susceptible to cold, and shouldn’t be exposed to temperatures below freezing. 

A young tree will die in temperatures around 27°F (-3°C). A mature tree is tolerant down to 25°F (-4°C), but this may damage the foliage. Short periods of cold are fine for a mature tree, but they won’t withstand prolonged periods of freezing temperatures. 

It’s not uncommon for a young tree to die back and sprout again in the spring. The roots are more cold-tolerant than the foliage. However, it will take several years for it to bear fruit in this event. Grow in a container if you know your winters can be freezing.  

The right level of humidity is vital to the development of this tropical evergreen. Too little moisture in the air can inhibit growth, while too much can result in fungal disease. Take care of growing in a greenhouse to keep humidity at a moderate level. 40-50% humidity is the minimum this plant needs for optimal growth. 

Fertilizing

‘Thai White’ guava trees are heavy feeders, and especially in their first year, you’ll want to fertilize often. Fertilize monthly in the first year, beginning with a 1/4 pound application, and increasing monthly to one pound at month four. 

In subsequent years, fertilize three to four times per year. Follow the directions on your specific brand of fertilizer, never exceeding 20 pounds per year. 

This plant will thrive on a balanced fertilizer formula with added magnesium. The ideal formula will be one of 10-10-10-4 or 6-6-6-2. Stop feeding during the tree’s dormant season, which is winter. 

Maintenance

A yearly application of mulch is important for your ‘Thai White’ guava. This will help to cushion and protect their shallow root system. Aside from mulching, pruning is necessary and varies depending on the age of your tree, as follows:

Young Trees

In the first year, prune your tree to about one to two feet tall. This will encourage lateral branch development, keeping fruit lower to the ground. 

As the tree branches, select three or four strong branches as the main branches. Allow these branches to grow to about two feet, and then tip them to encourage branching. 

To maintain this small size, make your cuts closer together, tipping branches closer to the trunk. Continue to prune branches more compactly for a mature tree that remains smaller. 

A tree planted in the ground is best kept to about 12 feet tall. Much larger and fruit harvesting will be more difficult. These will grow to about 20 feet tall if left to their own devices, but that makes the fruits at the top harder to reach. 

A tree between 10-12 feet is ideal for harvesting, as well as protection from strong winds. Make sure to prune away any crossing branches. This will improve airflow, which keeps fungal diseases to a minimum. It also preserves the strength of the surrounding branches. 

Propagation

Propagation from seeds is possible with this variety, and it will breed true. However, if you grow from seeds expect to wait up to eight years for fruit. Grafting is possible, but more commonly, air layering and cutting are the most successful ways to propagate and see fruit sooner. 

Cuttings

Take your cuttings of about six to eight inches from terminal branches that are recently mature. Your cuttings should have two or more leaves. Rooting hormone is an optional step, but using it will result in faster rooting. Cut your branches at an angle to give them ample rooting space. 

Use a moist, sterile potting mix to plant your cuttings in. Maintain moisture while your cuttings root, and keep them in a warm spot with bright, but indirect sunlight. 

Air Layering

Guavas also propagate well through air-layering, although this will produce a tree with a shallower root system. When you plant this tree, take care to loosen the surrounding soil adequately and water deeply to encourage deep rooting. 

Choose a branch that has a nice shape and some new branching. You want a branch that looks like it will make a pretty tree. About 12-18 inches from the end of the branch, score it in two places about an inch apart. Score just the bark all the way around the branch and scrape off the bark between the cuts. 

The roots will grow from the exposed area on the branch. Wrap this section in moist peat moss or sphagnum moss. Then wrap this section with plastic wrap or use an air layering ball. 

Check on your roots every two or three weeks to monitor development. Be gentle as you loosen the wrapping so as not to damage the tender new root tissue. 

Once the roots are substantial, cut the branch just behind the root ball. Your guava will have a better chance of survival if you plant it in a container initially, and allow the roots to develop more. You can plant directly in the ground though. 

It’s best to keep your young plant out of direct sun until it produces new growth. Then, move it to a location with full sun. 

Harvesting and Storage

‘Thai White’ guavas are most commonly harvested unripe. Harvest while the skin is still green and the fruits are firm. They will continue to mature after picking. They will ripen more slowly in the refrigerator but faster if you leave them on the counter. 

Store your guavas in the fridge for longer keeping. You can also freeze them. Other preparations for guava fruits include a sweet paste, syrups, and jams. 

Common Problems

The sweetness of these fruits is an attractant for insects. They also grow best in higher humidity, which can make them more susceptible to fungal diseases. 

Pests

Guavas have a high sugar content and a sweet aroma. Because of this, they are attractive to many types of pests. The most common types of insects that may show up are fruit flies, whiteflies, scales, guava moths, and red-banded thrips. 

Thrips, moths, and flies are among the easier issues to deal with. A strong stream of water will wash most of these away. Hand removal is a good way to deal with moth eggs. For scale insects, use a cotton swab soaked with 70% alcohol and wipe them away.

It’s important to keep your plant strong and healthy with proper watering and fertilizing. A strong, healthy plant can stand up better to the issues that come along with insect infestation. This is especially important for later growth stages when the tree is too large to inspect completely.

To protect fruit, I like to use organza bags drawn tightly on the stems, around each fruit. This is an effective way to protect your fruit without spraying it with pesticides. It’s better for you and the pollinators.

Diseases

Because they are tropical plants that grow best in warm, humid climates, Guava trees tend to struggle with fungal diseases. The humidity, paired with overwatering can lead to root rot and other fungal diseases. 

Some common fungal issues that crop up include anthracnose, stylar end rot, wilt, and pestalotiopsis (guava scab). If you see fruit damage, pick them off and dispose of them. This will help to reduce the spread of disease. Don’t eat affected fruit. 

Because these trees have shallow roots, root injury is another concern. Be careful when digging around your guava so that you don’t damage the roots. 

To help reduce fungal issues like algal leaf rot, keep the interior of your plant thinned out to promote airflow. Preventive anti-fungal sprays that contain sulfur help head off these issues before they occur. 

Iron Deficiency

Guava trees need a lot of iron, so iron chlorosis can be an issue. This is especially true of those planted in calcareous soils. Soil with a high pH, or soil that is alkaline, won’t break down the iron in a way that makes it available to the plant. 

Chlorosis appears in the form of young leaves that have pale tissue and dark veining. It can also affect the fruit, leaving them small and deformed. Brown leaf tips are another sign. 

Head this issue off by amending your soil before you plant. Use plenty of organic material to lower the pH of the soil. If you have chronically alkaline soil, you can use iron chelates made specifically for fertilizing alkaline ground. 

Frequently Asked Questions