Hoya Keysii is another form of Hoya Australis. Hoya plants are extremely diverse in terms of foliage, shape, and flowers. So far, about 600 to 700 Hoya species have been discovered. Many are still waiting to be discovered.
Hoya Keysii is admired for the lovely inflorescences, which resemble tiny decoration flowers on cakes. Hoya Keysii originates from Australia. The leaves of this plant are thick, fuzzy, and have a striking resemblance to those of Australis.
I like growing it in hanging baskets where it showcases the long, trailing vines. This rare Hoya is an interesting houseplant with fascinating white flowers and green foliage making it a classic evergreen plant.
According to The International Plant Names Index, Hoya Keysii belongs to Asclepiadaceae. It is a tropical and tender perennial that enjoys growing outdoors and inside.
- 1 Basic Plant Care Instructions for Hoya Keysii
- 2 Common Problems for Hoya Keysii
- 3 Tips for Growing
- 4 Frequently Asked Questions on Hoya Keysii
- 5 Conclusion
Basic Plant Care Instructions for Hoya Keysii
Hoya Keysii can be planted in either cactus soil or bark-based mixture. This species needs to be watered consistently in summer but sparingly in winter, and the humidity should always be above 60%. You have to protect this Hoya from chilly temperatures; the ideal temperature range is from 65 to 85 degrees Fahrenheit (15 to 29 degrees Celsius).
Hoya Keysii will thrive in any free-draining mix. Use a bark-based mix that has some horticultural pumice to it. This succulent plant also enjoys a cactus mix as a houseplant. Make sure the potting mix has excellent drainage abilities and a soil pH ranging from 6.1 to 7.5.
I like growing some of my Hoyas in my outdoor garden also; the perfect outdoor planting USDA hardiness zones range from 9b to 11.
This succulent variety enjoys long dry spells, so you do not have to worry much about watering it. Nevertheless, you still need to maintain regular watering. The frequency of watering will depend on three factors; light, temperature, and weather.
A simple rule is to water this species more in summer and less in winter. In fact, in winter, this Hoya might need to be watered once a month only.
To water, this plant moistens it thoroughly and let the extra water drain out of the pot. Next time you have to water your Hoya Keysii when the top half of the soil dries out.
Some Hoya species, including Keysii, like staying on the drier side, so they require a dry period of few days to start blooming.
Hoya Keysii needs good lighting for optimum growth. I would suggest a bright light that reaches your plant indirectly. Hoya Keysii cannot withstand direct, intense sun; therefore diffuses the sunlight to protect your plant from burning.
The harmful ultraviolet rays can break the chlorophyll in the leaves leading to reduced photosynthesis. Your plant will soon start losing its green color.
I have placed my Hoya Keysii 1-2 feet away from a south-facing window in my apartment, and it is thriving.
Hoya Keysii will flourish in temperatures that fall within the range of 60 to 85 degrees Fahrenheit (15 to 29 degrees Celsius). Most homes have their temperatures within this range; therefore, the temperature is not a big issue.
The only problem is cold weather; Hoya plants cannot handle chilly temperatures. If the outside temperature is getting lower than 50 degrees Fahrenheit (10 degrees Celsius), bring your plant inside. Else, it might suffer from chill damage.
If you are located in the northern hemisphere, I would suggest keeping heat mats near your Hoya plant to maintain the necessary warmth. You can even place the pot near a heater but not directly in front of a heater.
Originating from the tropical and subtropical areas, Hoyas like moderate to high humidity. Many Hoya varieties are humidity lovers, including this one, it likes more than 60%. But maintaining high humidity might be an issue, especially for growers that reside in dry areas. You can place your plant inside a sealed environment like terrariums to keep the humidity constant.
Below are some of my suggestions to create high humidity for your Hoya Keysii:
- Buy a humidifier and set it according to the humidity requirements of the majority of your houseplants. Humidifiers are the best option to increase humidity.
- The previous option is a bit costly. Therefore, you can use a pebble tray method if you are on a budget. All you need is a small tray filled with pebbles and water. Keep it under your pot. With time this water slowly evaporates and creates a high humidity environment.
- Group several high humidity Hoyas together; this will collectively increase the humidity for all of them.
The simple rule to decide what type of fertilizer should be applied is based on why you are feeding your plant. If you want your plant to have, more leaves add a high nitrogen fertilizer because nitrogen will encourage foliar growth. If you want to feed your Hoya Keysii plant for blooms, apply a high phosphorus fertilizer.
I apply a synthetic balanced or organic fertilizer only to save my precious plant from chemical burns. Since this one is a flowering variety, you can even add a bloom booster. You have to add this once you notice the flowers have started emerging.
My Hoya Keysii really enjoys Phostrogen or Osmocote as plant food.
Hoya plants are considered climbers because of the adventitious roots. These roots can not only absorb moisture but also cling to surfaces in the tropical forests. This plant grows epiphytically; therefore, you don’t have to repot it very often.
I refresh the substrate for all my houseplants every 2 or 3 years. I would suggest using a terracotta pot because it is porous and helps the plant in drainage.
A protip for successful repotting is to examine the root system of your plant before moving it to its new home. This will help you identify any unhealthy, rotting roots that might hinder the growth of the plant. Immediately trim the roots that have a weird mushy texture.
Every gardener likes their plants green and colorful. Therefore, I would suggest pruning any brown or dead stems to maintain the pleasing appearance of your plant. If your Hoya is growing vigorously, you can prune it for size control. Start by trimming the unhealthy, decaying vines.
The only precaution while pruning a flowering Hoya is to never cut the peduncles because this is where the waxy blooms will appear.
After the flowers, the next reason for the popularity of Hoya plants is easy propagation. Spring is the best season to take some cuttings from your Hoya Keysii. You can follow the brief guide given below:
- It is extremely important to use thoroughly sterilized garden tools.
- For stem cuttings, you should focus on the mature vines from last season. These are the healthiest stems that can produce new plants. I would suggest choosing a healthy stem with 3 to 5 lush leaves on it.
- I always take cuttings that are at least 4 to 6 inches in size.
- Remove leaves from the lower part and dip the cut in good quality rooting hormone.
- Now take a small pot and fill half of it with good quality potting soil. You can use sphagnum moss or a sterile potting medium.
- Place the cutting in the soil; about an inch of the cutting should be under the soil. Now pour the extra soil to cover the node completely.
- Slightly press the top surface of the soil to firm it. Make sure your soil has no large lumps.
- Water the cutting to moisturize the soil thoroughly, but don’t let the soil get soggy.
- Hoya plants root very fast in high humidity. Therefore, take a sealable plastic bag to cover your cutting. Open this bag and spray some freshwater after 2 or 3 days. Opening the bag will also allow airflow.
- Your pot should be located in a sunny location with indirect sunlight.
- These cuttings will start producing tiny roots within 4 weeks, provided you keep the environment warm. You can use bottom heat for faster rooting.
- Once fully grown, your cutting can be transferred to a bigger pot for better growth.
Propagation is a great way to expand your Hoya collection, and you can take as many cuttings as you like. Within a few months, you can create your own urban jungle with plants grown from cuttings.
Each Hoya species has unique blooms with several color shades and scents. Hoya Keysii has lovely white blooms with red centers. If you are wondering how it smells, I can assure you it has a spicy fragrance that creates an aromatic environment within your house. The flowers have a waxy texture and are about 1 inch in size.
As an old saying goes, some Hoyas need more patience than others; this is true for Hoya Keysii. This variety will bloom from fall to winter, but you have to wait patiently.
This succulent plant has felted leaves that vary in shades of green. The leaves are thick, fuzzy with bronze layering. The fuzziness or pubescence is very noticeable on the new, young leaves and appears mostly on the undersides of the leaves. The leaves are soft-to-touch and have a spade-shaped.
This Hoya plant has an upright growth habit with vines that grow in all directions. It’s a vigorous grower that needs plenty of room to grow. Most mature versions reach a size of 4 ft. on average.
Hoya Australis subsp. Australis Silver Valley is often sold as Hoya Keysii, but this is a misconception.
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Common Problems for Hoya Keysii
The only thing that ruins the whole gardening experience is pests. This Hoya is also vulnerable to common pests like mealy bugs, aphids, spider mites. All these are sap-sucking bugs that like feeding on the foliage of your Hoya Keysii. The mealybugs mostly hide under the leaves, and the aphids are found near the flower.
Aphids mostly attack and feed the new growth on the Hoya Keysii. So if new leaves on your plant are deformed or chewed, be sure that some nasty bugs are present. You can control aphids with an insecticide or bug killer designed specifically for aphid control.
If you are looking for spider mites, look for dull leaves and silvery undersides of the leaves. You will also notice some fine webs at different parts of the plant.
The main indication of all these pests is a sticky substance called honeydew. All these insects suck plant nutrients and secrete this sticky substance.
These pests can become difficult to control because they spread from one plant to another. I would suggest ensuring proper plant hygiene to avoid them. To treat any infected houseplant, use neem oil or insecticidal soap. Spray this on the infected areas to eliminate these pests.
You should regularly mist all the foliage with clean water because dry climates facilitate the growth of these insects. For a heavy infection, you will have to use a reliable pesticide.
This is a plant fungus that causes gray leaves. The gray areas are most prominent in the middle of the leaves; this is because this part has the highest moisture content. This virus thrives in cold winter months when the light levels are low. The leaves start crumbling and turn mushy.
I would suggest disposing of the blighted parts of your Hoya plants, including the flowers, leaves, and stems.
These resemble small black flies that are found near the soil surface or the leaves. The larvae for fungus gnats live under the soil and feed on the roots or lower stem tissues, causing the plant to wilt. You should immediately drench the soil in water and treat the soil surface with an insecticide spray to eradicate the fungus gnats.
These larvae are legless worms, and they spin webs on the soil surface. Reduce overwatering and algae growth on the soil surface when possible.
This is a major problem for many potted Hoyas, and it goes unnoticed until the damage is visible on the leaves and stems. As the rot progresses, the roots change their color from gray to black and eventually turn mushy. You can use fungicides for large infections, but withholding watering is enough to control the spread of root rot.
However, I highly recommend trimming the unhealthy roots and transferring the plant to a fresh potting medium.
Tips for Growing
- Never hang this plant in a hot, sunny window because that will scorch your plant.
- Your plant requires more water in the summer season because of warm temperatures; therefore, check for dryness every few days.
- To encourage blooming, it is best to keep this plant in direct sun for 3-4 hours every day.
- The adventitious root system requires high humidity for root formation and growth.
- Overwatering should be avoided because it will only serve the plant negatively.
- Repeated spraying with horticulture neem oil is highly effective for pest control.
- Do not water your plant in the evening or at night because the leaves remain wet for too long. This moisture can host several diseases or fungus.
- Always ensure plenty of airflow around your plant.
- Store the cuttings in a humidity dome or plastic bag for better results.
Frequently Asked Questions on Hoya Keysii
How should I prepare my Hoya Keysii for summer?
Once your Hoya Keysii has passed the cold winter months, you can add some fertilizer and slowly start increasing the frequency of watering. You have to start with a low-nitrogen fertilizer and apply it sparingly since the plant has just entered the active growth phase.
My Hoya Keysii blooms do not have red centers, is something wrong?
Sometimes this variety has pale rose coronas instead of red, so you do not have to worry about this; it’s completely normal.
What are some of the things the Hoya Keysii dislikes?
This lovely houseplant is not fussy at all, but it dislikes overwatering, dark corners and direct sunlight.
Does this Hoya bloom only once throughout the year?
This plant blooms repetitively throughout the year.
My Hoya Plant has sticky sap on the leaves, what is that?
This sticky substance might be the flower nectar if your plant is blooming. Otherwise, it indicates honeydew, which is a sign of pest infection.
In simple words, Hoya Keysii is defined as an upright, velvety version of Hoya Australis. The Hoya Keysii has low water needs, and you have to keep it on the dry side to have the typical vining growth.
The pretty flowers are white and red with a spicy fragrance. The leaves are nearly round or spade-shaped, fuzzy, and appear as a moderate vine. On touching, you will notice that the leaves are soft but have a furry texture.
Place this plant on your bookshelf, window, or work desk to create a mini cascading green jungle. It will surely brighten up any corner of your apartment. I wish I could grow all the Hoya species within my indoor garden to transform my house into an urban jungle.
Marcel runs the place around here. He has a deep passion for houseplants & gardening and is constantly on the lookout for yet another special plant to add to his arsenal of houseplants, succulents & cacti.
Marcel is also the founder of Iseli International Commerce, a sole proprietorship company that publishes a variety of websites and online magazines.