How to Grow a Eucalyptus Plant Both Indoors and Out

Though native to Australia, eucalyptus has been found in the United States since the mid-1800s. Since then, the fragrant leaves of this ancient tree have found their way into an array of health products, such as vapor rubs and lozenges, and are a staple in spas across the nation. It’s also a welcome addition to floral arrangements and bundles well with other powerful plants, such as lavender. 

Eucalyptus is easy to grow from seed, and thrives in warm weather, especially in zones 8 to 11. Still, even if you live in zone 7 or below, you can grow and reap the benefits of eucalyptus during the warmer months or by providing the appropriate environment indoors. 

Ahead, we spoke to experts to learn more about how to grow eucalyptus from seeds and care for it after those first seedlings appear. 

How to Plant Eucalyptus From Seed 

Eucalyptus is incredibly easy to plant from seed. Simply follow these steps. 

Materials You'll Need

• Growing container (pot, tub, or seed tray, etc.) 
• Eucalyptus seeds
• Garden trowel
• Potting soil

Instructions

1. Fill your preferred container with potting soil. Though not required, Folsom recommends using a sand and vermiculate blend to reduce the risk of problems like fungi. 
2. Take a small pinch of seeds and place them in the soil about 2 millimeters deep. "Sprinkle on and lightly tumble them around until their lightly covered," says Folsom. 
3. Moisten your freshly planted seeds, being cautious not to fully wet the seeds. According to Folsom, you need only to gently water and keep it moist.

He further cautions that eucalyptus seeds are extremely small, explaining that a little pinch is all you need. "Don't plant a lot of seeds at first," he says. "Plant very few, and see what happens. And since the seeds are long enduring, hang on to those to plant more next year."

If you plan to transplant seedlings from the mother pot, Folsom notes that you should transplant them when they are young because they'll quickly become pot-bound, proving difficult to transfer later. He suggests that the best course of action is to sow them in the pot where you intend to keep them or transplant them when they're very young.

Caring for Eucalyptus 

With so many species of eucalyptus available, there are some variations from plant to plant. As such, it’s a good idea to read up on the growth and care specifics as they relate to your chosen variety. However, in general, the care requirements below can lead to successful growth. 

Light 

Eucalyptus thrives best in full sun, requiring six hours or more of sunlight daily. Potted plants should be placed near a window if they’re to remain indoors, while outdoor plants should be well positioned for optimal sun exposure. 

Soil

Eucalyptus plants grow best in soil that promotes drainage, making potting mixes with sand and vermiculite a good option. Mixes with perlite, peat moss, or sharp sand can also provide the required drainage. 

Water

While you want to avoid dry soil, both Folsom and Candice Mock, owner of Patchwork Planting, point out that eucalyptus plants should be grown in moist but not wet soil. "They require good drainage and moisture," says Folsom, "but they aren’t like plants like aroids that you’d want to keep really wet." 

For outdoor eucalyptus plants, Mock suggests a light spritz, especially on very sunny days, saying that baby plants that don't have well-established roots can dry out easily.

Temperature 

Eucalyptus thrives best in temperatures between 65 and 75 degrees Fahrenheit, though exact requirements and hardiness can vary by species. Year-round, outdoor growth is generally limited to the lower-tier states, says Folsom. 

Mock, who plants and harvests eucalyptus in a field in Northeastern Pennsylvania, waits until the ground temperature is around 60 degrees (70 to 75-degree air temperature) to plant seedlings. Then, she maintains stems until frost, which is typically around September. 

Fertilizer 

Container-grown eucalyptus can benefit from light fertilization using a slow-release fertilizer at the start of the season or a liquid feed occasionally. 

Types of Eucalyptus

There are over 700 of species of eucalyptus, with some growing into tall trees and others shrubs. Which one you grow will depend on your purpose. The species below are the most common. 

• Silver Dollar (E. Cineria): As the name suggests, this species of eucalyptus features round, silver leaves that grow in a shrub or smaller tree formation. It’s a great option for pots or containers and is drought- and salt-tolerant. This type of eucalyptus is favored by Mock, who says it’s typically seen in wedding bouquets. 
• Baby Blue (E. pulverulenta): This variety of eucalyptus has silver-blue leaves and an intense fragrance, making it a popular choice among florists. It’s similar to the silver dollar species but has smaller leaves. It’s perfect for container growth, and Folsom recognizes baby blue as a species that home gardeners commonly like to grow. 
• Cider gum (E.Gunni): This fast-growing species of eucalyptus can yield tall, hardy trees, though it can be pruned to be maintained in a pot. The leaves are small, round, and silver-blue in their juvenile stage. Once matured, the plant produces lance-shaped, blue-green leaves. 
• White-leaved Mallee (E.Albida): Another species that can easily be grown in a container, the White-leaved Mallee is a shrub variety that can reach 10 feet tall. Like Cider gum plants, the leaves transition over time, starting as smaller, white, ovate-shaped leaves to longer, dark green lance-shaped leaves. 

Pruning Eucalyptus 

When and how you prune your eucalyptus can depend on the type of plant you have and your intended purpose. Still, the best time to prune your plant is often in late winter or early spring. 

Always check the species-specific guidance on pruning to ensure you employ the right method for the variety of plants you have and your intended outcome—e.g., clippings for floral arrangement, landscaping shrubbery, etc. 

Coppice Pruning for Cuttings

Coppice pruning will help you create a multi-branched plant, perfect for collecting regular cuttings. This approach is ideal for younger trees as long as the trunk has reached 5 inches in diameter. Using a sharp saw, simply cut the tree at an angle about 1 to 18 inches above the root. 

Mock, who grows eucalyptus for use in floral arrangements and shower bunches, says she cuts her plants "closer to the ground, so that way it [will] send offshoots," so she can get additional cuttings from the plant. 

Standard Pruning for Trees

If you prefer a tall eucalyptus tree, you’ll want to be careful about where and how you prune. "In general, the big eucalyptus you don't prune. You just let them go because you want to get a leader," or the central stem of the tree, says Folsom.  

If you do choose to prune your eucalyptus tree, it’s best to wait until the tree reaches at least 10 feet and 2 years of age. At that point, you can remove lower branches that weren’t shed during growth. In the following years, you can reduce the height by about one quarter. 

Hedge Pruning

You can use a hedge pruning approach to shape eucalyptus in a pot. To hedge prune your eucalyptus, it’s best to wait until your plant is at least two years old. When it’s time, you can cut back the plant's height by about a third. 

Propagating Eucalyptus 

Propagating eucalyptus from clipping can be difficult. Since the seeds grow so easily, it’s often best to simply grow them from seeds using the process specified above.

Still, if you have clippings on hand and would like to attempt propagation, follow these steps. 

1. Use a clipping that is around 4 inches long and ideally cut from a tree during June or July. Remove any spouting leaves. 
2. Dip the tip of the stem in rooting hormone for at least 30 seconds. 
3. Plant the cutting in a pot with the rooted hormone end down and moisten the soil.
4. Cover with a plastic bag or clear wrap and keep in a location that allows for a consistent temperature of around 70 degrees until new growth appears. 

Commons Problems 

Eucalyptus can fall prey to a number of issues that you'll want to keep an eye on.

Powdery Mildew

Powdery mildew appears as a white, powdery substance on the leaves of the eucalyptus plant. While it’s unlikely this spore-based plant problem will kill your plant, it can reduce yield and diminish the appearance of your plant.  

To reduce the risk of powdery mildew, make sure your plant has proper airflow and water the plant at the base, avoiding leaves. If your plant shows signs of powdery mildew, you can trim off the affected stems. A fungicide spray appropriate for eucalyptus can further resolve the issue. 

Fungal Diseases

Fungal diseases, such as myrtle rust, initially leave purple spots on your plant. Once on the plant, the spores turn yellow and then gray. You can treat this issue using a fungicide on the affected area or by removing the affected stems. 

Another common fungal disease that may appear on your eucalyptus plant, especially during periods of excess moisture is Anthracnose. This fungus creates brown lesions on the plant and/or distorted growth of leaves and branches. Using a fungicide and pruning trees can help prevent and resolve the issue. 

Root Rot

If your leaves are yellowing and wilting, your plant may be suffering from root rot. This problem, which is caused by soil-based fungi, can also lead to brown and soft spots at the base of the plant's roots and stems. To reduce the risk of root rot, avoid over-watering and keep any mulch clear of plant stems. If root rot is detected, reduce moisture.