Hoya australis
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Hoya australis

Samoan waxplant · Wax flower · Porcelain flower

Tier 1 Difficulty: medium Water: low Light: full_sun Toxicity: low
Water every
7 days
Temperature
20–35 °C
Soil pH
5–6
Hardiness
Zone 8–11
Click count
1,056
Observations
14

Description

Source: leafsnap

Hoya australis is a flowering plant in the Apocynaceae family, native to Australia. It thrives in diverse habitats, including rainforests, woodlands, and coastal areas. This plant features thick, waxy, dark green leaves that grow on long vines reaching up to 6 meters. During the summer, Hoya australis produces clusters of fragrant, star-shaped flowers that range in color from white to pink, attracting pollinators such as bees, butterflies, and moths. Often grown as an ornamental houseplant for its attractive foliage and beautiful flowers, Hoya australis prefers bright, indirect light but can tolerate some shade. It thrives in well-draining soil and requires regular watering during the growing season, though it's essential to let the soil dry out slightly between waterings. Overall, Hoya australis is an easy-to-care-for plant with stunning blooms, making it an excellent addition to any indoor or outdoor garden setting.

Care Guide

💧 Water Every 7 days

The porcelain flower, native to Australia's humid environments, thrives in conditions with high humidity and consistent moisture. Once established, it becomes drought-tolerant. To care for this plant, water it weekly, allowing the soil to dry slightly between waterings. Known for its glossy leaves and star-shaped flowers, the porcelain flower flourishes in well-lit, humid areas such as bathrooms or kitchens.

Suggested frequency: Every 7 days
FAQ
What's the best way to water my Porcelain flower?

To ensure excellent root development, place a garden hose at the base of the plant. Be sure to avoid spraying the leaves directly. If the plant is outdoors and in direct sunlight, the leaves will need more watering. You can use bubblers to moisten the roots of each plant, as well as soaker hoses that cover the entire garden or bed. When adding or removing plants, use the soaker hoses to help roots go deeper. After watering, drain any excess water and allow the soil to dry before watering again. To prevent diseases, water at ground level. On sunny days, consider spraying the entire plant with water. Whether potted or in-ground, remember that Porcelain flower prefers deep watering rather than light sprinkling.

What should I do if I give too much or too little water to the Porcelain flower plant?

When a Porcelain flower is overwatered, its leaves can turn yellow and eventually drop off. The plant may also appear dull and unhealthy with mushy stems. In these cases, it's recommended to adjust your watering schedule when possible. Wilting can also be a sign of under watering, with crispy and dry leaves appearing instead. If the soil is dry and simply watering is not enough, a thorough watering is necessary. This will help the Porcelain flower recover, but the plant may still have dry and yellow leaves for a few days due to root damage. Once the plant returns to normal, the yellowing of leaves will stop. Indoor Porcelain flowers should always have their moisture levels checked to avoid overwatering. If black spots are present, allow the soil to dry in the pot by refraining from watering for a few days. Overwatering can lead to root rot, indicated by discolored and slimy roots. If this occurs, consider transferring the plant to a different pot. Always take preventative measures to avoid root rot and ensure the soil does not become too soggy. When planting Porcelain flowers outdoors, be sure to dig a little deeper and check the soil moisture level with your fingers. If the soil is too dry, it may indicate underwatering, in which case adequate watering is required to help the plant recover.

How frequently should I water my Porcelain flower?

The Porcelain flower prefers to be watered deeply but infrequently, especially when planted in pots. Potted plants have limited water storage, so the soil tends to dry out faster. If you live in a cold region, you should water the plant every 3 to 5 days. Water it in the morning when the soil is dry, both indoors and outdoors. You can check if the plant needs water by feeling the soil. If the top 2-3 inches of soil are dry, it's time for a thorough watering. On hot days, check the soil moisture daily as the heat can dry out the pot quickly. If you have a garden, you'll need to irrigate the soil regularly as well. In hot climates, you may water once a week. Only water when the top 2-3 inches of soil are dry, both indoors and outdoors. Take into account the amount of rainwater the plant receives to prevent over-watering and root rot. If there is sufficient rainfall, you may not need to water the plant additionally. Porcelain flower usually grows in spring and fall. When outdoors, use mulch about 3 to 4 inches deep to retain water. For sandy soil, water more frequently as it drains faster. Clay soil requires less frequent watering, as it retains moisture. Keep track of watering dates on a calendar and pay attention to drooping leaves, which may indicate a need for water.

How much water does my Porcelain flower need?

The Porcelain flower typically needs about a gallon of water on a regular basis. For potted plants, it's best to water them deeply until you see water dripping from the bottom of the pot. Then, wait for the soil to dry before watering again. You can use a water calculator or moisture meter to determine how much water you've given the plant each week. During the flowering period, provide ample water but allow the moisture to evaporate afterwards to avoid root rot. If the Porcelain flower is planted outdoors and receives sufficient rainfall, it may not need extra watering. When the flower is young or newly planted, make sure it gets 1-2 inches of rain per week. As the Porcelain flower matures, it can rely solely on rainfall. Only during excessively hot weather or prolonged periods without rainfall (2-3 weeks) should you consider giving the plant a thorough watering during the cooler hours of the day to prevent damage from high heat. Additional watering will be necessary during extended dry spells.

Do I need to water my Porcelain flower more or less depending on the season or climate?

The Porcelain flower needs to be outdoors and relies on rain for watering, unless the weather is persistently dry. During the spring and fall, the soil should be kept moist but not soggy, alternating between dry and moist conditions. In the summer, hot weather causes water to evaporate quickly, so you may need to water more often to keep the soil moist. During winter, the Porcelain flower needs less water as it goes dormant. You can use well-draining soil like terracotta to help with water evaporation. Once the flower begins to leaf out and go dormant, you can stop watering and let it rely on fall and winter rains. The Porcelain flower prefers good drainage to avoid ponding or drought. If it's in a pot, provide regular watering, especially in summer, and ensure adequate drainage to prevent cold and wet roots. Water the entire root system deeply once or twice a week, avoiding shallow sprinkles that can encourage fungal growth. Even during dormancy, don't let the flower dry out completely. Avoid overwatering and provide good drainage to prevent plant death in winter. Apply mulch for stress reduction, water conservation, and healthy blooms.

☀️ Light Full sun

Originating from naturally light-loving habitats, the porcelain flower grows best in full sun but can, to some extent, tolerate reduced sunlight. Strong light promotes healthy growth. However, it is not tolerant of excessive exposure, which can cause damage, and too little light slows its growth.

Ideal: Full sun
FAQ
How much sunlight does Porcelain flower need to grow?

Tropical ornamental plants that thrive in full sun require at least 6 hours of direct sunlight each day. These plants are well-suited to areas with strong and direct sunlight, as they need this light to flourish. In their natural habitats, they tend to grow in open fields or along forest edges, where they can enjoy abundant sunlight all day long.

What will happen if the Porcelain flower doesn't get enough sunlight?

Tropical ornamental plants that need full sun may face issues if they don't receive enough sunlight. They might become leggy and weak, and their leaves could turn yellow or pale. Furthermore, they may stop producing flowers. Ultimately, if these plants continue to lack the required amount of direct sunlight, there is a possibility that they may die.

What happens if Porcelain flower gets too much sunlight?

Tropical ornamental plants that thrive in full sun require ample direct sunlight, but excessive exposure to intense sunlight can harm them. Prolonged periods of direct sunlight can cause sunburned leaves or the development of unsightly brown spots. Additionally, if the soil dries out too rapidly in full sun, these plants may become dehydrated.

How do you prevent Porcelain flower from getting too much sunlight?

To protect tropical ornamental plants that thrive in full sun, it's important to find a spot with ample direct sunlight but some shield from the intense midday heat. If you're growing these plants in containers, you can move them to a shadier area during the hottest hours to shield them from excessive sunlight. Another option is to offer shade using a shade cloth or umbrella during the peak heat of the day.

🌡️ Temperature 20–35°C

La porcelain flower procede originalmente de un entorno templado donde las temperaturas fluctúan entre 68 y 95 °F (20 a 35 ℃). Prefiere el calor, aunque puede adaptarse a temperaturas más bajas si es necesario. En las estaciones frías, favórele el crecimiento regulando la temperatura interior para imitar su hábitat natural.

Ideal temperature: 20–35°C
FAQ
What temperature is best for Porcelain flower?

To help your tropical plants thrive, it's best to maintain a temperature range of 75℉ to 90℉ (25-32℃). While different species can tolerate temperatures outside this range, sticking within a few degrees of these limits will ensure optimal growth. However, there are extreme temperature limits to be aware of. Anything below 50℉ (10℃) or above 95℉ (35℃) can hinder growth and cause issues with the leaves and stems. Low temperatures are particularly damaging, as even a light frost can lead to the death of your tropical plants. In fact, cellular death can occur rapidly, with some species dying within 12 to 24 hours.

Does the Porcelain flower need to be exposed to different temperatures during different stages of growth?

Porcelain flower can undergo different growing phases without needing temperature changes, but it is important to maintain consistency. Any wild fluctuations in temperature can slow down its growth, regardless of the phase it is in. Therefore, it is best to keep Porcelain flower in a controlled environment. The optimal temperature range for this plant species is between 75℉ and 90℉ (25-32℃), with maintaining a temperature above the lower limit being particularly important. Although temperatures above 90℉ (32℃) are not ideal, Porcelain flower, being a tropical plant, can tolerate them to some extent. However, temperatures below 50℉ (10℃), especially 40℉/5℃, can cause direct damage to this heat-loving plant species.

Does the Porcelain flower require varying temperatures throughout the year?

The porcelain flower plant does not require different temperatures for different seasons. To properly care for the plant during different seasons, it is crucial to maintain the environment within the optimal temperature range. Therefore, it is recommended to keep the plant indoors. By doing so, you have control over the temperature, regardless of the outside climate. For tropical species like the porcelain flower, adequate light is also important. These plants prefer partial to side-level sun exposure. This means that any light they receive should be dappled or filtered, with bright but indirect light being the best choice when growing them indoors. Exposing the plant to too much direct sunlight can harm the leaves and reduce its potential for growth.

What temperatures should you keep your Porcelain flower at to keep it healthy?

Here are three tips to help you take care of your plants: 1. Keep your plants away from windows during colder months: Cold air can leak into your home through cracks in the windows, and any plants placed near them will be affected. Move tropical plants to an area with bright but indirect light, while avoiding potential drafts. 2. Watch out for dry patches, which may indicate too much sunlight or heat: If you notice white or scorched leaves, your plant may be getting too much heat or sunlight. This can lead to dehydration and hinder growth. Dry spots can spread and eventually cause your plants to die if left unaddressed. 3. Be cautious of frost: Colder temperatures and frost can damage plants by disrupting their water circulation. This can lead to a lack of moisture in the stems and leaves. Look out for signs of hydrosis (a water-soaked appearance) and if the issue persists, the plant may shrivel and turn dark brown or black, eventually leading to death.

How can I keep my Porcelain flower at the right temperature?

To maintain the ideal temperature for Porcelain flower, it is important to monitor both the climate and humidity. Ideally, you should keep each species in a room with climate control to mimic its natural habitat. It is also crucial to monitor humidity levels, as they impact temperature. To increase humidity, you can use a humidifier or lightly mist the leaves. If you plan to grow this species outside, it may be challenging to maintain the right temperature and humidity balance. In such cases, it is best to bring the plant indoors where you can control the climate more effectively. Creating an indoor growing space will help your plant thrive.

💨 Humidity normal (40-60%)

This plant will thrive in moderate humidity, which is probably the level in your home. However, misting it a few times a week can be very beneficial. Make sure the room has good ventilation.

Humidity: normal (40-60%)
🪴 Soil 5-6
Soil pH: 5-6
🌱 Fertilizer

The best time to fertilize a Porcelain flower is in early spring, as it breaks dormancy. This encourages overall growth and flower development. Fertilizing improves foliage, stems, and branches, while encouraging large, bright, and long-lasting blooms. It helps transport nutrients from the roots to the flowers and enhances the plant's health and resistance to disease.

FAQ
Why should I use fertilizer on my Porcelain flower?

Fertilization is vital for the overall health and well-being of a Porcelain flower. It ensures that the plant receives the necessary energy and nutrients to develop healthy foliage, sturdy stems, and branches. The flowers are especially valuable to gardeners, and fortunate

When should I fertilize my Porcelain flower?

To properly fertilize a Porcelain flower, the best time is in early spring after its dormant phase and before buds open. This provides enough energy for overall growth and flower development. However, there is also an option to feed it in the fall, but this does not need to be as large of a feeding. Some gardeners fertilize while planting, but this may not always be necessary.

When is the best time to not fertilize my Porcelain flower?

During the winter, Porcelain flowers do not need to be fertilized like many other plants. In this dormant phase, they do not require much energy from the soil to grow. Fertilizing during this time can lead to overfertilization and negative effects. The best times to feed a Porcelain flower are in early spring and fall. This means that during most of the spring and summer, fertilization is not necessary. It is also a good idea to refrain from feeding if the plant is subjected to hot or dry conditions.

Which kind of fertilizer should I use for my Porcelain flower?

When choosing a fertilizer for Porcelain flower plants, it is generally better to use a specific type of fertilizer rather than a general-purpose one with even ratios of nitrogen, phosphorus, and potassium. Typically, nitrogen and phosphorus are the most important nutrients for Porcelain flowers, so a fertilizer with higher volumes of these nutrients compared to potassium is recommended. A fertilizer with an N-P-K ratio of 10-10-8 or something similar should be suitable. Additionally, it can be beneficial to use organic materials like compost for one of your annual feedings. Granular fertilizer is commonly used for Porcelain flowers.

How can I make my Porcelain flower grow better?

Fertilizing your Porcelain flower is a simple task that any gardener, even those with minimal experience, can do. To apply granular fertilizer, just sprinkle it on the soil after moistening it with water. You can also improve the soil by adding organic material like compost or manure. Place the material on top of the soil and use a hand rake to gently work it into the top few inches without disturbing the roots.

🪴 Pot & Repot 2-3 years

Repot the Porcelain flower in early spring, choosing a pot only slightly larger than the current one with proper drainage. Use a well-draining potting mix and position the root ball at the same level as before. Gently loosen any root-bound roots. After repotting, water generously and place it in a warm, shady location. Regular pruning helps keep its size down and encourages new growth.

Suggested frequency: 2-3 years
✂️ Pruning

Porcelain flowers have waxy leaves and fragrant blossoms. To encourage growth, prune them in early spring by removing leggy stems and damaged leaves. Avoid heavy pruning to retain older wood, which helps promote air circulation and prevent pests. Always use clean, sharp tools for pruning, and consider consulting local gardening resources for additional care advice.

🌿 Propagating
🐛 Diseases & pets
☠️ Toxicity

Hoya australis plants are not toxic to humans or animals. It may even be healthy food for your dogs and other animals. However, when ingested in high quantities, it might induce gastrointestinal pain.

Characteristics

Plant Type
Vine
Life Cycle
Perennial
Genus
Hoya
Family
Apocynaceae
Hardiness Zone
10
Mature Height
3.96 m to 10.06 m
Mature Spread
30 cm
Leaf Color
Green
Leaf Type
Evergreen
Flower Color
White
Flower Size
2.54 cm
Bloom Time
All year round
Planting Time
Spring, Summer, Autumn
Harvest Time
All year round
Native Area
Tropical Asia, Australia

Tags (17)

Common Names (3)

en Samoan waxplant
en Wax flower
en Porcelain flower