Complete Eucalyptus Genus Guide

21 Feb 2022

The eucalyptus genus is comprised of many stunning species including trees, shrubs, and potted plants. It’s a great addition to your houseplant collection and well worth the care you put into growing one.

In this article, we’ll take a detailed look into how exactly to grow and care for a thriving, healthy eucalyptus plant.

Main Characteristics

The eucalyptus belongs to the Myrtaceae family and is mainly found across Australia and the Philipines. It’s classed as a dicotyledon which means that it’s a flowering plant whose seeds usually contain two embryonic leaves.

In Australia, it’s commonly referred to as gum trees and stringyback trees. There are many eucalyptus trees, however, we’ll be focusing on growing one as a houseplant. As a potted plant, you can treat it as you would an annual or perennial.

It sprouts thick, leathery, and waxy evergreen leaves that give off a refreshing aroma. These are covered in oil glands which prove to have numerous health benefits that we’ll be discussing later on.

Fun fact: The name eucalyptus actually means “well covered”.

Benefits

Just like many other houseplants such as the English ivy, this plant has tons of health benefits. The leaves shouldn’t be consumed as this can cause a few negative side effects, however, it has great medicinal value when inhaled, consumed as a tea, or applied topically.

Here’s a list of the benefits:

  • It contains antioxidants that assist in protecting your body from free radical harm and oxidative stress.
  • Its often included in cough syrups as it relieves flu-like symptoms.
  • The sap is found in numerous psoriasis treatments.
  • Eucalyptus tea has also been shown to decrease stress levels.
  • Studies have shown that it can fight off bacteria causing tooth decay.

Fun fact: Its leaves form a large portion of the koala bear’s diet due to its medicinal properties and benefits.

Eucalyptus Plant vs. Eucalyptus Tree

The major difference between a eucalyptus plant and a tree is the size. Typically, a tree can grow up to 330 feet (100m) tall while a potted plant is obviously much smaller.

A tree is grown outdoors and planted in soil, whereas, the plant or shrub is grown in a container. This would then mean that the care a eucalyptus tree and plant need will differ.

What Does It Symbolize?

It’s considered a holy tree to many Aboriginal tribes in Australia. The plant is said to fight off negative energy and is often used to spiritually cleanse a person.

Due to its medicinal properties, the plant also represented purity. Additionally, it was thought of as symbolizing the division between heaven and Earth.

Types of Eucalyptus

This genus includes approximately 750 different species. Each type grows foliage in a variety of colors, sizes, and shapes. Let’s take a look at five commonly found eucalyptus.

  • Eucalyptus cinerea: This is by far one of the most popular houseplants and is also known as ‘silver dollar’ eucalyptus, ‘argyle apple’, and ‘mealy stringybark’. It produces compact growth and silver-green foliage.
  • Eucalyptus gunnii: It’s also named the ‘cider gum’ and ‘Tasmanian cider tree’. Its bark is smooth and sprouts upright growth. It’s interesting to note that the foliage has a silver-blue color which turns into a blue-green color as the plant matures.
  • Eucalyptus radiate: This plant is also commonly called ‘narrow-leaved peppermint’ as it grows elongated, green leaves with a lemony scent.
  • Eucalyptus camaldulensis: It is also known as the ‘red river gum’ and ‘Murray red gum’ as its grey bark has a tint of red.
  • Eucalyptus platypus: It’s a relatively hardy species and produces round, green leaves. Its bark will usually come off in strips during the summertime.

How Big Does It Get?

The size of a potted plant will differ greatly from that of a tree. The typical houseplant can reach a height of between 6 to 10 feet (1.8 – 3m) and produce a spread of around 2 to 15 feet (0.6 – 4.5m).

How Fast Does It Grow?

It is a fast-growing houseplant that will shoot up an extra 3 feet (0.9m) of growth a year until it reaches its mature size.

How Long Does It Last?

Its lifespan will differ according to the care it receives. When looked after well and grown in optimal conditions, a potted plant can live for 20 to 30 years.

Fun fact: A eucalyptus tree can survive for a whopping 250 years.

Toxicity

The leaves produce a sap that contains an oil called eucalyptol. When this chemical is consumed in large doses it can even be fatal and have severe effects.

Is Eucalyptus Safe for Cats and Dogs?

The leaves are highly toxic when consumed by your cat or dog. The sap can cause detrimental health effects that should be treated as soon as possible.

It causes the following symptoms:

  • Excessive salivation
  • Vomiting
  • Diarrhea
  • Depression
  • Fatigue
  • Seizures
  • Confusion

It’s imperative that you seek advice from your vet if you suspect that either of your pets has consumed the leaves.

Is It Poisonous to Humans?

The oil found in the leaves is toxic to people too. In large doses, the sap can cause damaging effects on your health and you will need to seek professional medical advice if you have eaten it.

We’ve listed the potential side effects:

  • Nausea
  • Vomiting
  • Diarrhea
  • Coma

Eucalyptus - size, lifespan, toxicity, growth speed (infographics)

Eucalyptus Plant Care

In this section, we’ll take a look at the care your eucalyptus needs to survive and thrive. You can use this information to formulate the ultimate care regime.

How Much Water Does It Need?

A eucalyptus is slightly drought-tolerant which means it doesn’t require a lot of water. Overwatering it may even cause it to die. It should only be watered when the top 2 inches (5cm) of the soil is dry.

Typically, you’ll need to water it once or twice a week during the spring and summertime. It shouldn’t be watered more than once a week during the cooler months as it usually only requires a drink once every two weeks in autumn and winter.

Drainage

Many houseplants require excellent drainage such as the hosta. The eucalyptus plant’s health can be negatively affected without good drainage. Improper drainage may cause the plant to become waterlogged which leads to a fungal infection.

It needs to be grown in fast-draining soil and a pot with drainage holes. You can also add some sharp sand to the potting mixture to ensure a free-draining environment.

When and How to Trim It

This genus doesn’t need to be pruned often and only requires any damaged or unhealthy foliage to be trimmed off. You may also want to prune any overgrowing stems if you wish to maintain its current size.

The best time to prune it is during the summertime and always ensure that your tools are sterilized before you begin snipping away.

Follow the steps below:

  1. Start cutting off the lower level stems and make sure to snip them off by the base of the main plant.
  2. When you prune the stems and leaves, you will need to cut them off at a slight angle.
  3. You can simply pluck off any unhealthy leaves if you don’t want to remove an entire stem.
  4. Check the soil to determine whether your plant needs to be watered and then place it back in its original position.

Repotting

The eucalyptus needs to be repotted once every 2 to 3 years during the springtime. Transplanting is necessary to keep the plant healthy and prevent it from becoming root-bound.

Look at the steps listed below:

  1. Water the plant deeply at least 24 hours before transplanting it. This will help alleviate any stress experience as it’s repotted.
  2. Find a pot that is about 1 or 2 inches (2.5 – 5cm) larger and fill it with fresh soil.
  3. Loosen the plant and gently slide it out of its container.
  4. Repot it in its new home and water it well.
  5. You can then care for it just like you previously did.

Winter Care

It requires special care during the winter as it doesn’t do well if left in temperatures below 50°F (10°C). There are a few ways to maintain a healthy houseplant during the cooler months.

The plant will need to be watered less frequently as it doesn’t need as much moisture. Additionally, you should cease feeding it as this plant isn’t actively growing.

You should also place it in the brightest area in your home so that it can keep warm under the bright sun. Ideally, it will need to bask under the light for at least 8 to 10 hours a day.

Environment Conditions

Does It Need Sun?

It absolutely loves bright sunshine! You should place it under full sunlight for at least 6 to 10 hours a day. It doesn’t do well in shady areas so make sure to place it by a bright windowsill as this will promote healthy growth.

You may want to monitor your plant’s foliage during the summertime as harsh sun rays can scorch the plant. If this happens then place it under indirect light during the afternoon.

Best Soil

The eucalyptus prefers slightly acidic soil just like the caladium. The optimal pH level is between 4.5 and 7.5. Furthermore, the potting mixture must be well-draining, airy, and loose.

It will even do well in sandy soil that allows for quick drainage. A soil that retains too much moisture will harm the plant’s roots. If you choose a sandier mix then add a handful of compost to increase the nutrient density.

You can also create your own mixture by adding 1 part soil, 1 part peat moss, and 2 parts compost or perlite. Another create combination is 2 parts compost and 1 part perlite.

Can It Grow in Water?

People sometimes add these beautiful green-blue stems to a floral arrangement. However, the cuttings won’t root or grow in the water and typically only look healthy for around 3 weeks before dying. Therefore, we don’t recommend doing it.

Fertilizer

You should feed this genus once a week during the spring and summertime. The best type of fertilizer is one low in nitrogen and phosphorus while including a higher quantity of potassium.

It prefers being fed with a liquid and water-soluble fertilizer with a ratio of 10-30-10 or 10-10-10.

Pot Size and Type

The best type of pot is a clay or terracotta one as they provide the perfect environment for the plant. A porous pot allows for good airflow to the roots and it dries the soil out faster.

As it grows relatively quickly, you should use a container that is 4 inches (10cm) wider than the rootball.

Temperature Tolerance

It produces vibrant and healthy foliage when grown in temperatures between 65 to 75°F (18 – 22°C). It can even survive temperatures as high as 90°F (30°C).

Just like the poinsettia, this houseplant won’t survive if grown in temperatures below 50°F (10°C).

Humidity Level

The average household humidity level is perfect for this houseplant. It shouldn’t be grown in a location where the relative humidity level is above 40 percent.

This makes your life way easier as you won’t need to mist the plant or put in the effort to increase the humidity level surrounding it.

Outdoors vs. Indoors

Eucalyptus’ can be grown in your garden if you reside in USDA hardiness zones between 8 and 11. Many owners actually end up transplanting them outdoors as they often outgrow their containers. This will encourage rapid growth and it may even bloom if planted in the right position.

When growing it outside you will need to shelter it from any wind and make sure that it receives plenty of bright sunshine. To ensure that it isn’t lacking in any nutrients you should continue fertilizing it.

The only issue when planting it outside is that it cannot survive cool winters. If you live in a particularly cold climate then it’s best to keep the eucalyptus inside.

Eucalyptus - care, water, light, soil, pot, temperature, fertilizer (infographics)

Flowering

A tree may produce pretty flowers, however, a potted eucalyptus rarely ever blooms. If you’re eager to watch your plant flower then we suggest transplanting it to your garden.

An outdoor plant will sprout clusters of cone-shaped flower buds in groups of three. These will then open during the summertime and produce red, white, or pink blossoms.

How to Grow Eucalyptus

This houseplant is typically bought as a small potted plant, however, there are two ways that you can grow your own. You can do this by either propagating a stem cutting or planting its seeds.

How to Propagate It from Cuttings

A healthy stem cutting can be propagated in soil during the summertime. You should be warned that this method is often unsuccessful.

Check out the steps listed here:

  1. Prepare a small container with some potting soil and perlite.
  2. To encourage growth and root development, it’s best to add a slow-releasing fertilizer.
  3. Use a pair of scissors to snip off a 5 inch (12.7cm) long stem with at least 4 leaves attached to it. You don’t want to cover any leaves with soil, so you’ll need to pluck off those located on the lower half of the stem.
  4. Cover the cut area in rooting hormone and plant the cutting.
  5. Keep the soil slightly moist by watering it every few days, and position it under bright light.
  6. In 4 to 8 weeks, the cutting will root and you can then water it less often and place it under full sunlight.

Top tip: To enhance your chances of successful propagation, you should use a cutting from a young plant that is between 2 to 12 months old.

Growing from Seed

Planting its seeds will require some patience and planning. First, you will need to prepare the seeds for germination before planting them. Once they have been planted and sprouted new growth, you’ll know that this process was a success.

Below is a step-by-step guide:

  1. Put the seeds in your refrigerator for 2 months during mid-winter. They should remain in temperatures between 37 to 41°F (3 to 5°C).
  2. Fill a small container with a moist seed starting mixture or compost.
  3. Sprinkle the seeds across the soil and lightly cover them with a potting mixture.
  4. Lightly mist the seeds to maintain a good level of moisture, and find a sunny home for them.
  5. They will germinate in 2 or 3 weeks, and you’ll need to transplant them once they’ve grown 6 inches (15.2cm) tall.

How to Keep It Alive

A eucalyptus’ foliage and roots will become diseased when the plant receives inadequate care or if it’s grown in improper environmental conditions. We will discuss what may be causing a few major issues and how to remedy the problem.

Why Are the Leave Turning Brown?

When it’s suffering from transplant shock or a fungal infection then the foliage will brown.

The plant may experience some shock and stress when it is repotted. You can water it before transplanting it to lessen this stress. You will have to give it time to recover and after a week the plant should adapt to its new home.

The most effective way to treat a fungal infection is by transplanting it to fresh, nutrient-rich soil.

Root Rot

Root rot occurs when the plant has been overwatered for a prolonged period of time. The foliage may become brown and the roots will turn into a black-brown color. You may also notice that the stem is soft and limp too.

You will have to remove the plant from its current container and snip off all of the diseased foliage and roots. Then you can repot it a well-draining potting mixture.

Yellow Foliage

Its leaves will lose their lush, green color and become yellow when it is grown in an overly moist environment. It is either being overwatered or placed in a humid area.

You will need to allow the soil to dry out slightly before watering it again. Additionally, you should avoid misting the plant and find a new home where it is less humid.

Last Comment

The eucalyptus makes for a lovely houseplant and with the right care, you’ll grow a thriving one. Always make sure to water it correctly and provide it with bright sunshine then you’re all good to go.

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