Gardenia Tree: Care and Growing Guide (Watering, Pruning and More)

Gardenia Tree: Care and Growing Guide

The gardenia tree is a beautiful small tree with lush evergreen foliage, brilliant white showy flowers, and an intoxicating fragrance. Although gardenia is a shrub, it is possible to have a braided gardenia or a single trunk plant that grows like a small, flowering tree. This means that you can grow a topiary gardenia tree indoors in temperate climates and outdoors in subtropical or tropical gardens.

This article is a complete guide to growing a gardenia tree in your garden or a container. In addition, you will get helpful tips on caring for this tropical flowering shrub-like tree and how to resolve any growing issues.

Gardenia Tree (Gardenia jasminoides) Facts

Gardenia Tree (Gardenia jasminoides)

Gardenia tree

Gardenia tree is an evergreen shrub with single or braided stems trained to grow like a tree. The beautiful white-flowering plant has a thin trunk, rounded crown of thick, glossy, leathery dark green leaves, and brilliant-white, showy flowers that bloom from spring through summer in USDA zones 8 to 11.

Typically, a gardenia tree grows 2 to 7 ft. (0.6 – 2.1 m) tall and 2 to 3 ft. (0.6 – 1 m) wide. You can grow gardenias as flowering annuals in temperate climates. Or plant in pots and overwinter them indoors. Also, they thrive throughout the year in Florida and other southern US states.

Related reading: Stunning flowering trees for Florida.

Gardenia trees and shrubs are native to tropical and subtropical regions of the world.

Other names for the gardenia tree include cape jasmine or jasmine rose. The evergreen plant is famous for its heavily scented white flowers with a rose-like appearance yet are reminiscent of jasmine flowers.

How to Care For Gardenia Tree Outdoors

To care for a gardenia tree outside, plant it in full sun or light afternoon shade in organically rich, fertile soil. Provide at least 1” (2.5 cm) of water weekly to keep the soil moist. Prune the gardenia tree annually to maintain its shape. Fertilize every four weeks during the growing season.

How to Care For Gardenia Tree Indoors

To grow a gardenia tree indoors, plant the tree in well-drained, acidic, peat-based soil. Gardenias require at least four hours of sunlight daily. Water the potting soil thoroughly when the top 0.5” (1.3 cm) is dry, allowing excess water to drain. Putting the pot on a pebble tray with water can increase humidity.

Gardenia Bush vs. Gardenia Tree

gardenia shrub

Gardenia shrub with single-petaled blooms

A gardenia plant grows as a multi-stemmed shrub that can be trained as a topiary tree. The tender stems of the gardenia bush are braided and supported to make them grow as a slender trunk, or it can be trained as a single trunk tree where the most upright stem is chosen to become the trunk of the tree. With care and pruning, the gardenia tree then develops a rounded crown, giving the tree a lollipop-style look.

Gardenia Flowers

Gardenia Flowers

Gardenia flowers can be single or double blooms, depending on the cultivar

Gardenia flowers are incredibly fragrant, large, creamy white, waxy blossoms that stand out beautifully against dark green glossy leaves. The flowers can be single or double blooms with slightly ruffled ivory white petals surrounding a yellowish center. Depending on the cultivar, white gardenia flowers can measure up to 4” (10 cm) in diameter.

The gardenia tree blooms from mid-spring through summer. The summer blooming gardenia tree has aromatic white blossoms and the tree sometimes reblooms in late summer if you deadhead spent flowers. However, it’s good to remember that harsh afternoon tropical sun and dry weather can impact gardenia flowers, causing them to drop.

To ensure a potted gardenia tree blooms indoors, it’s vital to control the temperature. Fluctuations in temperature or standing for many hours in direct sunlight can damage gardenia flower buds. The ideal temperature for flowering is an average of 70°F (20°C).

Growing Gardenia Tree in a Pot Outdoors

A potted gardenia tree is ideal for growing in a container garden, on a patio or deck, or next to an entranceway.

The best potting soil for growing gardenia trees outdoors is a mix of equal parts potting soil and peat moss, amended with perlite. Place the potted gardenia tree in a sunny spot, protected from the afternoon sun. Water whenever the top layer of soil dries out, usually about once a week.

Tips for growing a potted gardenia tree outdoors:

  • Potted outdoor gardenia trees require more frequent watering than growing in the ground.
  • Fertilize the tree once a month to promote flowering.
  • The pot for a gardenia tree should be clay or terracotta for stability.
  • Choose a pot that is 6” (15 cm) wider than the plant’s root ball.

Growing Gardenia Tree Indoors

For most people, the only option to grow a stunning gardenia tree is in a pot indoors. This allows you to put the sun and heat-loving plant outdoors during summer and take it inside in the winter. Unfortunately, gardenia trees are notoriously tricky to grow indoors.

The potting soil for a gardenia should be two parts peat moss, two parts potting soil, and one part perlite. Place the potted gardenia tree in a sunny location but protected from direct sunlight to avoid leaf scorch. Water the tree whenever the top 0.5” to 1” (1.3 – 2.5 cm) is dry.

To encourage blooming indoors, it’s vital to pay attention to temperature and humidity. A gardenia tree requires around 50 percent relative indoor humidity. So, you may need to use a humidifier or a pebble tray and water. During winter, central heating can dry the air; therefore, ensure enough moisture to prevent stressing the tree.

The minimum temperature range for gardenia trees is 50°F to 59°F (10°C – 15°C), so bring it indoors when the temperature drops below that. However, a minimum temperature indoors of 61°F to 65°F (16°C – 18°C) is the best for growing.

Tips for growing a potted gardenia tree indoors:

  • Keep the potted gardenia tree away from direct heat sources
  • Adding coffee grounds to the potting mix helps to increase acidity
  • Rotate the plant pot monthly to keep growth even

Related reading: How to water indoor plants.

How to Overwinter Gardenia Tree

A gardenia tree can’t survive outdoors during winters in zones 7 and below. Outdoor temperatures below 15°F (-9°C) can affect the plant’s growth, and it risks dying in the freezing cold. Therefore, it’s necessary to overwinter a gardenia tree indoors. Even in zone 8, protecting a gardenia tree from frost may be required.

In the warmer regions of zone 7, you may need to use a frost blanket to protect the evergreen tree from damage. You can use cardboard boxes, bed sheets, or buy a frost blanket from the garden store. It’s also a good idea to put a thick layer of mulch around the root area for added frost protection.

To overwinter a potted gardenia tree, you should think about bringing it indoors after it’s finished flowering. The first task is to check for pests and treat the foliage with a neem oil solution if necessary. Then, place the potted tree near a sunny, south-facing window, protected behind a sheer curtain. Finally, water it deeply to keep the soil moist whenever the top 1” (2.5 cm) dries out.

Where to Grow Gardenia Tree

A gardenia tree can be challenging to grow because it has specific requirements. For example, the tropical tree needs at least four hours of sunlight daily. However, the scorching afternoon sun and damp, alkaline soil can negatively impact its growth. Therefore, it’s vital to choose the right location indoors or outdoors to grow the tree successfully.

Where to grow gardenia tree indoors

A potted gardenia tree grows best near a sunny window, away from cold drafts or hot radiators. So the best place is at an east-facing window where it gets plenty of sunlight in the morning and early afternoon. Or you can put it near a sunny south-facing window with some protection.

Where to grow gardenia tree outdoors

The best location in your garden to grow a gardenia tree is in the sunniest spot with some afternoon shade. The optimal place is an east-facing exposure to get plenty of morning and midday sunshine. In addition, gardenia trees don’t like to be crowded, so ensure enough spacing between other plants.

Gardenia Tree Soil 

The flowering evergreen gardenia trees thrive in well-drained, fertile soil that is constantly moist. However, it’s vital to prevent the ground from drying out or being too soggy. To ensure optimal growth and flowering, work in rotten manure every spring to boost soil nutrient content.

When to Plant Gardenia Tree Outdoors

If you live in zones 8 to 11, the best time to plant a gardenia tree is in the fall. At this time, the ground is still relatively warm, and the roots get plenty of time to establish themselves. You can plant a hardy gardenia tree in zone 7. However, it’s best to plant the gardenia tree in spring after the threat of frost has passed.

How to Plant Gardenia Tree

Planting a gardenia tree is relatively simple. After deciding on the best location and buying a suitable nursery tree, you are ready to plant the gardenia in the ground.

To plant the gardenia tree, dig a hole twice as wide and the same depth as the root ball. Remove burlap and any covering from the roots and detangle them. Next, set the gardenia tree into the hole, the same depth as it was growing before.

Next, backfill the hole with native soil amended with compost. Remember to press down as you go to eliminate any air pockets. Then, thoroughly water the ground to help the roots establish themselves. Lastly, spread a 2” to 3” (5 – 7.5 cm) layer of mulch over the root area to lock in moisture.

How to Care for Gardenia Tree

Gardenia trees are a beautiful addition to any garden landscape. Growing as a braided tree or topiary tree, gardenia produces masses of fragrant white flowers and lush evergreen foliage. The good news is that a gardenia tree thrives when it gets enough sunlight and moisture.

Here is a guide on ensuring that a gardenia tree grows to its maximum potential in your southern garden.

How to Water Gardenia Tree

Water the gardenia tree often enough to keep the ground moist without becoming too soggy. Gardenia trees suffer when they grow in overly-damp ground, or the ground dries out. Drip irrigation is an excellent way to keep the soil consistently moist in subtropical landscapes.

You may have to water a gardenia tree every other day or twice a week in hot, dry weather. However, you should never allow the root area to become completely dry, or leaves may turn yellow and drop.

Potted gardenia trees growing outdoors require frequent watering. Before saturating the potting soil, check that the top 1” (2.5 cm) is dry. Then pour enough water until it drips out the pot’s drainage holes.

Fertilizing Gardenia Tree

Gardenia trees growing in the ground and pots benefit from regular fertilization. Use a shrub fertilizer for flowering plants that grow in acidic soil. It is also necessary to follow the instructions and not over-fertilize the shrub-like trees; otherwise, you could burn the roots.

Apply a water-soluble fertilizer monthly from spring until the end of summer. This is approximately between April and September. Don’t fertilize the gardenia tree in the fall or winter. This could stimulate new growth that will quickly die.

You can also apply a slow-release fertilizer in spring or work in plenty of organic compost to encourage vigorous flowering.

Pruning Gardenia Tree

Pruning a gardenia shrub is necessary to encourage it to grow as a tree. You should remove the side stems on younger trees to leave a robust central stem to grow as a tree. Some people successfully create a topiary gardenia by braiding the three main stems. However, it’s usually easiest to buy a nursery tree.

Gardenia trees benefit from regular pruning after they have finished flowering. In early fall, cut off spent blooms and remove straggly branches. You can also prune back the stems by two-thirds to encourage vigorous flowering the following spring. Pruning also helps improve air circulation and healthy growth.

Propagating Gardenia Tree

Taking stem cuttings is the best way to grow a new gardenia tree. First, cut a 4” (10 cm) length of a healthy stem just below a leaf node. Next, remove all the leaves apart from the few at the top end of the stem. After that, dip the cut end into rooting hormone.

To root the gardenia tree cutting, fill a small pot with a mixture of potting soil and perlite. Push the cutting 1” to 2” (2.5 – 5 cm) into the soil and seal a clear plastic bag over the cutting to increase humidity. Then place the cutting in bright indirect light.

Keep the soil moist by misting it regularly. It should take four to six weeks for roots to form. After that time, you can transfer the rooted gardenia tree to a larger pot. Then, continue growing it in a sunny, indoor location.

Repotting a Gardenia Tree

Typically, it’s necessary to repot a gardenia tree every two to three years. Usually, the gardenia tree has become rootbound by this time, and you may notice roots poking out the drainage holes. Repotting is best done in early spring. Remember to choose a pot one to two sizes larger than its current one.

Pests and Diseases Affecting Gardenia Tree Growth

Gardenia trees are prone to insect infestations and root diseases. The most common pests to affect gardenias are aphids, spider mites, mealybugs, scale, and whiteflies. In addition, issues with excessive moisture or poor air circulation can cause powdery mildew, sooty mold, or anthracnose. Typically, growing a gardenia tree in optimal conditions keeps it healthy and robust.

A neem oil spray is the best way to rid a gardenia tree of common plant bugs. Mix 2 tsp. organic neem oil with 1 tsp. liquid Castile soap and a quart (1 l) of water. To kill bugs on the gardenia tree’s foliage, spray the neem oil liberally over all the foliage, including the underside of leaves. Repeat the process every seven days for the best results.

Powdery mildew is a waxy, white, fine coating caused by a fungal foliar infection. Typically, the problem results from too much humidity and cool air around the leaves. The best way to deal with this unsightly condition is to increase air circulation and avoid splashing water on the leaves.

Related reading: How to get rid of powdery mildew.

Root rot caused by soggy or waterlogged soil can cause yellowing leaves, wilting, and leaf drop. You can sometimes notice root rot when repotting a gardenia tree because it will have signs of brown, mushy roots.

The best way to manage root rot is to ensure proper watering techniques and adequate soil drainage. Gardenia trees planted in the ground can benefit from growing in a raised bed. For a potted gardenia tree, the pot must have drainage holes. Only water the gardenia trees when the top layer of soil is dry.

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