Hoya Pubicalyx Care and Management Guide

The Hoya Pubicalyx is a flowering plant belonging to the Hoya genus species and is known to be native to the Philippines. This plant has lanceolate and succulent foliage and has a vining growth habit, so it grows epiphytically. It grows well as a houseplant in the temperate climatic regions and is also available in the variegated forms in some gardening stores and nurseries. Often its leaves are mottled with slivery variegated flecks and the level of variegation is dependent on its exposure to sunlight. There are numerous cultivars of this species and growers can decide according to their personal preferences.

The Hoya Pubicalyx produces star-shaped fragrant flowers of purple, pink and red color. The color of flowers is dependent on the type of cultivar and the level of care and management. On average the mature plants can reach a height of about 8-10 feet. Its leaves are narrow and their size ranges between 5-12 cm in length and 5-6 cm in width. This plant is also known as a wax plant because it produces glossy and thick leaves. It is a low-maintenance plant and requires minimal care for growth, but growers must do some care to avoid compromised and stunted growth.

USDA Zones

This plant grows well in the USDA hardiness zone 10. It can also be grown indoors in the other zones, but the management of the right conditions, temperature, and humidity is a must factor to ensure good growth.


This plant grows well in well-drained and good structured loamy soils. Growers can add good quality and contaminant-free compost, organic matter, and potting mix to improve the properties of growing media.


This plant grows well in the soil pH range of 6.5-7.5. Although slight fluctuation from this range will not cause major damage to the growing plants the management of the right pH according to the mentioned range is significantly important to ensure good uptake of nutrients by the plants. Growers can always adjust the pH of the soil and grow media by the addition of amendments after pH testing.

Sunlight Requirements

Hoya Pubicalyx grows well in the presence of indirect and medium to bright sunlight. This plant can be placed near the window in indoor conditions. The use of grow lights is greatly recommended for the areas that are not receiving enough sunlight to support their growth. The plant must be protected from the intense direct sunlight in outdoor conditions. It is also possible to protect the plant by covering it with a clean cloth that can allow some aeration and sunlight penetration.

Never place the plant in the bright sunlight during the peak sunny hours as it can cause scorching and leaf burning. Healthy growing and blooming plants require at least 6 hours of exposure to the indirect bright sunlight so growers must manage the lighting requirements accordingly. Various scientific studies have shown that placing this plant in the morning and evening sunlight for 1-2 hours helps to grow beautiful foliage.

Watering Requirements

Hoya Pubicalyx is a drought-tolerant and hardy plant so it can grow well even after some negligence. The fact is that all growing plants need some water to continue metabolic activities and nutrient absorption from the soil. Therefore, controlled regular watering must be done during the growing season. Growers can make a watering schedule according to the prevailing climatic conditions and soil moisture contents. Checking the moisture levels in the soil is the best way to avoid watering stress and diseases. Check soil moisture by inserting fingers in it and water if the upper 2 inches of the soil is dry. A light sprinkling of water is enough if the only top layer is dry. More watering intensity is required if the subsoil in the container is also dry.

Growers should not allow the subsurface to get too dry as it will negatively affect the microbial communities and soil biota. The use of filtered water or rainwater is greatly recommended for this plant as it encourages better growth. Impure and contaminated water can cause adverse effects on its growth and maturity so growers must avoid tap water for this plant. The watering requirements of this plant are moderate, and the average watering frequency is only once in 7 days in the winter season and two to three times a week during the summer seasons. The watering requirements of growing plants greatly vary according to the prevailing climatic conditions.

Plants need less water on cloudy days during the summer seasons so estimating the soil moisture contents is greatly recommended before the next watering. Moreover, the watering requirements are also variable according to the nature of growing media. Hoya Purbicalyx grown in the peat-based grow mix requires optimal watering. Whereas these plants grown in the lighter soil mix requires deep watering until the applied water starts escaping the drainage holes. Never allow the water to stand in the soil or grow mix as it can cause root rotting, leaf dropping, and development of diseases. Discard the excess water immediately after the drainage and don’t allow this water to stay in the saucer. This is rewarding and easy to grow plant and forgive the skipping of 1-2 irrigations.


Maintain the temperature between 5-25 degrees Celsius in indoor conditions. This plant is sensitive to frost so avoid growing in the cold outdoor regions. Never allow the indoor temperature to fall too low as it can cause direct death of the plant.


It is a tropical plant so it loves to grow in humid conditions. Maintaining 60-70% humidity in the surroundings is the best way to support good growth. The use of humidifiers is the best way to improve humidity in drier climates. Gently mist its leaves by using a water spraying bottle. Evaporation of water creates enough moisture around the growing plant to support its humidity requirements.

Avoid misting at the budding and flowering stage as it can cause reduced flower formation. It is important to note that plants need less water when its surrounding is more humid so growers must avoid overwatering in humid climatic conditions. Also keep these plants at some distance from air conditioners, heaters, and vents.


This plant is not a heavy feeder, but its growth is greatly improved by the application of fertilizers. The use of organic fertilizers is greatly recommended as synthetic chemicals are harmful to surroundings, soil health, biodiversity, and ecosystem functioning. The application of liquid fertilizers with a high dose of potassium helps to promote flowering in this plant. A monthly dose of diluted fish emulsion and compost tea also helps to improve soil quality and plant growth on a sustainable basis.

The use of inorganic fertilizers is not inhibited but it is important to maintain a good balance of organic and inorganic fertilizers. Fertilization at the start of blooming season and bud formation helps to ensure good quality and larger-sized flower formation. The plant goes under dormancy during the winter season so avoid fertilizing the plant at this time. Always do watering after fertilizing because the best use and uptake of fertilizers can only be ensured when the soil is damp.

Some common nutritional deficiency symptoms for this plant are as follows.

Potassium deficiency: It causes the appearance of the tan color on the leaf edges and closer growth of new leaves on the stems.

Phosphorus deficiency: It causes the appearance of rust color on the leaf edges and completely ceases the new growth.

Nitrogen deficiency: It causes yellowing of lower and older leaves followed by falling off and stunted growth due to lack of chlorophyll.


Each flower can reach a size of 0.4 cm and numerous tiny flowers join together to make a bouquet-type cluster. These clusters appear on the tips of peduncles and are connected to the main stem via a stem-like tiny structure. Late spring to late summer is the peak flowering time for this plant. Its flowers produce a strong fragrance that is even more prominent at the night. The flowers are also waxy and grow on the smaller stalks having a length of less than one inch.

The plant can start blooming after 1-2 years of planting and the flowering initiation is variable according to the type of cultivar, care, management, and prevailing climatic conditions. Removal of stalks after blooming season should be avoided because it can delay the blooming time. Allowing the old stalks to stay on the plants helps to grow new flowers in less time. Moreover, it also helps to save the energy that the plant has to use for the development of new stalks. More blooming can be ensured by keeping the plant in the sunlight, but direct exposure of the plant to intense and scorching light should be avoided.


It is a low-maintenance plant and can survive well with little care and no pruning. Spring and summer season is the ideal time for pruning this plant. Pruning after the blooming season is also helpful to ensure better growth and development. Trimming leaves from the lower plant parts helps to improve the overall look and beautification of the plant.

Prune larger growing stems and plant parts and use these for new growth and propagation in the new pots. It is important to remove all damaged, and dead stems, yellow leaves, and diseased parts to avoid the further spread of the problem. Always wear gloves during pruning and cutting because the sap from the cut parts can cause skin allergy.

Hoya Pubicalyx Growing Tips and Guide

  • Use fertile, loose, and well-draining soil.
  • Frequently water the top 2-3 inches of the soil to avoid drying.
  • Place the plant in bright but indirect sunlight for better growth.
  • Maintain the temperature between 10-25 degrees Celsius for indoor growth.
  • Grow the plant in the plant outdoors in the recommended zones only as otherwise it will be killed by the temperature extremities.
  • Maintain 60-70% humidity level in the surroundings and use humidifiers and dehumidifiers if required.
  • The plant has a trailing growth habit so provide some support to allow climbing.
  • Fertilize plants at least once a month during the summer and spring seasons.
  • Regularly check the plants for disease attacks and insect pest populations.
  • Prune it in the spring for aesthetic purposes only. However, removal of diseased and dead parts is a must practice.
  • This plant is not toxic but can cause some skin allergies, irritations, and health concerns so are careful while cutting and dealing with the sap.

How to Propagate Hoya Pubicalyx

Propagation through leaf-cutting and stem cutting is the ideal and easiest way of propagation. Spring and summer are active growing seasons for this plant and growers must propagate it during this time to get good results.

  • Use sterilized scissors or pruning shears to prune the plant. The gardening tools can also be sterilized by using isopropyl alcohol.
  • Cut five to seven inches cutting from healthy growing stalks having good nodes.
  • Remove all the leaves on the lower end.
  • Place the cuttings indoors in the shade to allow the healing of tissues.
  • Plant the cuttings in the soil or grow medium by keeping the nodes in the soil to a depth of about 4 inches.
  • Generously water the soil three times a week to keep it moist until the start of the growing season.
  • Keep the plants in a humid and warm place where they can receive bright indirect sunlight.
  • Root development can be observed 3-4 weeks after planting the cutting in the soil.
  • The rooted cutting can be repotted after to boost new growth and development.
  • Choose a partially shady and sunny location to protect foliage from burning.
  • The use of zip lock and plastic bag method is also helpful for propagating the Hoya Pubicalyx.
  • Placing the cuttings in the potting mix and sphagnum moss helps to produce better growth than the soil media alone.

Growing Hoya Pubicalyx from Seeds

This plant is very easy to grow from seeds but the selected seeds must be of good quality and free from contaminants.

  • Store the seeds in the dry and dark location to get good germination and vigorous seedlings.
  • Sow the seeds in a good quality potting mix or peat moss-based soil mixture.
  • Provide enough humidity and light to ensure germination.
  • The maximum temperature during the daytime should be maintained at about 25 degrees Celsius.
  • Sow its seeds indoors to ensure better germination.
  • Regularly water the soil to keep it moist. Avoid overwatering.
  • Cover the container or pot with a plastic bag for protection of the plant from cold and wind.
  • Germination can be observed after two to five weeks of sowing and germination time is dependent on environmental conditions.

Potting and Repotting Hoya Pubicalyx

This is a vigorously growing plant and can gracefully and easily spread on all sides of the pot. Therefore, the selection of the right pot size and type is greatly important to get better looks. It is not a root-bound plant, so repotting is not a major requirement for its better growth and development.

This plant requires good drainage and climbs upward so the provision of some vertical support will be helpful in both aspects. The use of terracotta pots is also a good choice to ensure good drainage. While the use of larger containers is essentially helpful to keep this plant root-bound.

Common Problems and How to Treat

Hoya Pubicalyx is a long-lasting, rewarding, and easy to manage plant and can be easily grown in containers. Growers can place it both indoors and outdoors and can be placed in the windowsills, patios, and porch. However, the presence of insect pests and diseases can cause severe damage to its foliage and flowers. Its flowers and sweet-smelling can attract numerous pests and bugs.

  • Mealybugs

Mealybugs are common pests infecting all Hoya species and can be controlled by using insecticides and proper management. Spray the plants with neem oil and water spray to remove mealybugs. Rub isopropyl alcohol-based cotton swabs on the leaves and stems to kill mealybugs.

  • Aphids

Aphids are commonly found on all household plants and can be seen on the backside of the leaves, base of stems, and flower buds. These can be easily removed from the plants by using the gentle water stream from the hose, insecticidal soap sprays, organic and inorganic pesticides. The use of inorganic and chemical-based pesticides is greatly discouraged as these are harmful to pets, children, beneficial insects, and the environment.

  • Whiteflies

Whiteflies are sap-sucking smaller insects that are commonly found on indoor plants. The population of whiteflies especially rises during the summer season so growers must be more careful at this time. Their higher infestation can cause leaf drying, falling, and yellowing. The use of yellow sticky traps is the best way for monitoring and control their populations. Optimal use of insecticidal oils and soaps also favors reducing whiteflies populations on a sustainable basis.

  • Root Rot Nematodes

Root rot nematode is the worst pest of Hoya Pubicalyx and can cause significant quality losses. Some of the major symptoms of this pest include stunting, yellowing, and wilting. These nematodes survive well in the warmer areas and can cause the complete death of plants in case of severe infestations. These nematodes cause damage to the rooting system of the plants and thus the overall health of plants is negatively affected.

Growers must remove the infected plants immediately to prevent further spread. Seed treatment before sowing and soil treatment before planting helps to minimize the root rot nematode infestations on the plants. The addition of organic matter and compost to the soil or growing medium is also helpful to promote the biological control of root rot nematodes.

Disease Development

Most of the Hoya Pubicalyx diseases develop due to overwatering and are related to soil moisture or fungal infections. Maintenance of moderate moisture levels is significantly helpful to reduce the problem of disease development.

  • Sooty Mold

It is also known as black mold and usually develops on the leaves of numerous plants. It makes nectar-like sugary liquid and appearance of black spots on the leaves. Nectar from flowers and honeydew from the pests are major reasons for sooty mold development on the plants. It can be easily removed from the plants by gently wiping with a wet paper towel or cloth. Immediate removal of pests and nectar flies is also helpful to reduce the appearance of sooty mold on the plants.

  • Blight

Blight is specifically a fungal infection and it can affect all parts of the growing plants. Common symptoms of blight include the appearance of gray patches on the stems and leaves of the plants. Severe infections can lead to the mushy appearance of plants and leaf drooping. Further spread of blight can be reduced by immediately removing the infected parts.

The use of copper-based fungicides is also a recommended approach to get rid of blight. However only recommended concentrations of this pesticide should be used to avoid adverse effects on growing plants. Lowering environmental humidity, avoiding overwatering, and misting are also helpful to reduce the blight problem on a sustainable basis.

  • Leaf Yellowing

Yellowing of older and lower leaves is a sign of trouble and can be avoided by using proper care and management. Avoiding overwatering, allowing proper exposure of the plant to sunlight, and controlled irrigation scheduling are the best practices to avoid leaf yellowing. Moreover, fertility testing is also a good way to get an idea about the nutrient deficiencies and toxicities in the soil because nutritional imbalances can also cause leaf yellowing.

Varieties of Hoya Pubicalyx

  • Royal Hawaiian Purple

This plant has green leaves with specifically greyish or silver patterns and produces black or pinkish-red clusters of flowers.

  • Red Buttons

This variety produces dark, purple-colored flowers having a reddish center. Purple and red blotches are also evident on its green leaves.

  • Black Dragon

This variety produces lime green leaves without any marks and black flowers with red centers. The blooming of this plant can be achieved by placing in the optimal sunlight or providing light by the means of artificial grow lights.

  • Pink Silver

This cultivar produces green leaves having silver splashes. The color of its leaves turns pinkish silver in the presence of sunlight and thus it is named pink silver due to this feature. Its flowers have light red color and pink colored small centers.

Some other popular varieties of this plant include silver sheen, jungle garden, dapple gray, and bright one.


Is it possible to remove hard water spots from its leaves?

Yes, these spots can be easily removed from the leaves. Take a pint of red or white vinegar and add it to the warm water to make a solution. Dip a small paper towel, or clean cloth in the prepared solution and gently rub the leaves in a circular motion. Properly rinse the leaves with contaminant-free water and dry the rinsed leaves with another paper towel or cloth.

Why is my Hoya Pubicalyx plant not blooming properly?

Less exposure to light is the most common reason for no blooming in the Hoya Pubicalyx. Blooming can be achieved by keeping the plant in the bright indirect sunlight and providing all essential inputs most appropriately.

Is it possible to train these plants to grow in a specific path?

Growers can easily train growing plants to grow along a specific path such as these can be directed to climb at any wall, tree, or hanging planter in the home. These plants have vining growth habits and can grow to a length of 20 feet by the proper training. Any vertical support or bamboo can be placed in the center of the pot. It is also possible to tie the strings and twines so that plants can spread in all possible directions or patterns.

Is the Hoya Pubicalyx toxic in nature?

This plant contains milk-type fluids in its structure that have toxic nature. Contact with this sap or consumption of this fluid can cause skin allergy and health issues. Therefore, pets and children should not be allowed to touch this plant.

Is the Hoya Pubicalyx a succulent?

Hoya Pubicalyx is not a succulent plant. Although it has waxy leaves, it does not belong to the category of succulents.

Does the Hoya Pubicalyx have a deep rooting system?

Hoya Pubicalyx has an epiphytic rooting system and can grow on other plants and trees. Typically it has a shallow rooting system in the soil so can be easily grown in the pots and containers

Where to buy the Hoya Pubicalyx?

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