Hoyas are an interesting genus of plants. With over 500 species, this group has many leaf shapes, textures, growth habits, and sizes. They are known for their low-maintenance disposition and the unique and sweet-smelling flowers they produce.
Hoya kerrii is an intriguing species with a vining habit. However, it is most commonly sold as a single leaf. In the weeks leading up to Valentine’s Day, this sweet little succulent becomes a popular plant to gift to anyone who enjoys caring for houseplants.
The nicknames “sweetheart vine” and “lucky heart plant” hint at why this plant is so popular in February. You see, this plant’s pretty heart-shaped leaves can be planted on their own in a small container, looking like a tiny plant heart. It can be kept alive in this fashion for years!
In addition to being simply adorable, it is an easy plant to care for. This is a great beginner plant and wonderful for anyone who falls on the underwatering end of the plant care spectrum. Let’s talk about how these plants grow and how you can care for your own Hoya kerrii.
Overview
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What is Hoya Kerrii?
This succulent vine grows up to 13 feet in the wild.
Hoya kerrii is a vining, flowering succulent that can grow up to 13 feet long in the wild. In cultivation, it tends to be a much smaller plant, typically reaching about two to three feet long or tall, depending on how you choose to grow it.
You can train this plant to climb a small trellis or moss pole, and it can also be grown in a hanging basket where it will trail rather than climb. However you grow it, it is a lovely plant that asks little of its caretaker aside from bright light and occasional watering.
Native Area
The plant is native to Southeast Asia, including Northern Thailand and Vietnam.
Hoya kerrii is native broadly to Southeast Asia. More specifically, it was first recorded in the mountains of Northern Thailand. Its native range also includes Vietnam, Laos, South China, Cambodia, and the island of Java in Indonesia.
Characteristics
This epiphytic plant grows on trees or rocks like orchids.
Like most other plants in the Hoya genus, H. kerrii is epiphytic or lithophytic, meaning that in its natural environment, it grows in trees and from rocks rather than in soil, as terrestrial types do. As a result, the care needs of the plant are similar to other epiphytic plants, such as orchids.
The leaves are heart-shaped, leading to their popularity around Valentine’s Day and many cute nicknames. You can purchase H. kerrii as a single leaf, which may live for several years. However, you are unlikely to see any further growth or additional leaves; it will always stay as a single leaf this way.
The stems are thin and woody as they mature, with leaves that grow in pairs from the central stem at intervals. The leaves are leathery with a glossy sheen and can be solid green or variegated.
In early summer, this Hoya produces hanging peduncles of flowers. The flower clusters comprise many small, star-shaped white flowers with red centers. These flowers are not typically fragrant, but they do produce a lot of nectar, which is wine-colored and has been known to leave stains on clothing and furniture.
Uses
This Hoya purifies indoor air and has traditionally been used for herbal remedies.
Generally, H. kerrii is an ornamental plant grown as a houseplant for its attractive foliage and flowers. As houseplants go, they are very good at removing volatile organic compounds (VOCs) from the air inside the house.
Historically, Hoya plants have been used medicinally for several purposes. This plant is considered non-toxic for pets and humans but can cause stomach upset if consumed in large quantities.
Where to Buy
They are widely available in stores and online due to their commonality and ease of shipping.
This is a fairly common species of Hoya, and because of its heart leaf shape, it can be found readily at certain times of the year. I see this plant regularly at my local nursery and home improvement stores alongside other houseplants.
This plant is also very easy to find from online retailers. It is a sturdy, very drought-tolerant plant, so it is not difficult to ship long distances. Some rarer varieties are easier to find this way.
Planting
Hoyas thrive outdoors in zones 10-12, favoring heat and rocky environments.
Hoyas are typically only grown outdoors in zones 10-12. They are heat-loving plants that like to grow in trees and rocks and do not tolerate cold weather. North of zone 10, H. kerrii is mainly sold and grown as a houseplant.
How to Grow
Hoya kerrii is low maintenance, needing very little attention from its caretaker as long as it is provided with the right environment. You will need a spot with ample sunlight and where the temperature doesn’t fluctuate much.
Light
They prefer bright but indirect lighting, such as filtration through tree shade.
Hoyas grow in trees in their natural environment, with either climbing or trailing growth habits. This growth habit is known as epiphytic growth. They have relatively high needs in terms of sunlight but cannot tolerate much direct sunlight.
The ideal exposure situation for H. kerrii is for the plant to receive an abundance of indirect or filtered sunlight. Placing your Hoya beside a window that experiences sun exposure for most of the day will keep it happy. Another way to achieve this effect is by hanging a sheer curtain to diffuse the light if it’s too bright.
Water
These succulent plants require infrequent watering because their thick leaves store water.
Hoyas are succulent, so they don’t need to be watered often. In general, Hoyas with thicker leaves can be watered less than those with thinner leaves, as those thick leaves store more water for the plant to use during drought.
Do not let your plant dry out between waterings. A good way to tell whether or not it needs to be watered is by feeling the leaves. Hoya leaves that are well watered will be thicker and stiffer. The leaves will become more flexible and soft as the plant dries out.
If you notice your plant’s leaves getting softer and more bendable, it is probably time to water. Use room temperature water and water about every two weeks during the spring and summer. As the weather cools, your Hoya will enter dormancy, requiring less water. To prevent root rot, water sparingly in the winter only when the leaves indicate the plant is thirsty.
Soil
Hoyas need well-draining soil due to their vulnerability to overwatering.
Because Hoyas are vulnerable to overwatering and susceptible to root rot when watered too often, soil is a very important piece of the care puzzle for these plants. The soil needs to have excellent drainage, more than the average terrestrial plant.
Hoyas can tolerate more water retention in the soil than most orchids can, but soil amended with orchid bark is a great way to contain your Hoya. If you start with a standard potting mix, you will want to heavily amend the soil with large particles to increase drainage.
Amending your potting soil with peat moss, orchid bark, perlite, or vermiculite will help increase drainage, keeping your plant’s roots from remaining damp. Cactus potting mix is another good medium for potting this plant.
Temperature and Humidity
H. kerrii thrives with typical household humidity levels of around 40%.
Humidity is not a major issue for H. kerrii. Although this is a tropical plant, it doesn’t require the same amount of humidity that other tropicals need to stay hydrated because the leaves retain a lot of water. Your Hoya will be happy with the average household humidity level of around 40%.
Temperature is more important to this plant than other environmental factors. Hoyas like a warm and consistent temperature without extreme fluctuations. This is part of what makes them such great houseplants. The ideal temperature for them is between 60°-85°F.
Move your plant away from windows when you expect an extreme drop in the outside temperature because this can also affect the temperature indoors. Many plant owners don’t realize how cold it can get inside a window when the weather outside is very cold.
Fertilizing
Hoyas need diluted all-purpose liquid fertilizer monthly during their active growth phase in spring and summer.
Hoyas are not heavy feeders. They have very similar needs to other succulent plants in this way. When your plant is actively growing and producing flowers in spring and summer, you can fertilize once a month. Use all-purpose houseplant fertilizer, preferably liquid, and dilute it to ½ strength.
In the fall, your Hoya will begin to enter dormancy, meaning its needs will decrease significantly. It will need less light, less water, and, likewise, less fertilizer. You can stop fertilizing entirely through the winter and resume in the spring when the plant re-enters an active growth stage.
Maintenance
You can prune hoya plants to control size and foliage density.
Pruning Hoya plants is not a necessity, but it does have its place in their care. Pruning your H. kerrii can be done as a means of controlling the size of the plant, although this is a very slow grower, so that will typically not be necessary.
You can also prune to control the density of your plant’s foliage. Pruning to thin out or thicken up the foliage is a more common practice with this plant. If you hard prune your Hoya, expect that flowering will be delayed, or the plant will not flower in the following year at all.
Hoya kerrii likes to be a little bit root-bound, so repotting is not something that you will need to do regularly. These plants will bloom better if they are root-bound, which is typically the desired result. Repotting should only need to be done about once every three years, and select a pot that is only one to two inches larger.
Growing in Containers
Use a snug pot with ample drainage.
Because they are usually grown as houseplants, your Hoya kerrii will most likely be a container plant. In the same way that they need well-draining soil, they also need a container with excellent drainage to help stave off fungal root rot.
Pot your Hoya in a pot that is slightly larger than its nursery pot to keep it snug and encourage it to bloom. Make sure that the container has ample drainage in the way of drainage holes in the bottom of the pot. Clay orchid pots work very well for containing Hoyas.
Propagation
These plants propagate best through stem cuttings for successful growth.
You may hear from certain sources that Hoya kerrii plants can be propagated by leaf cuttings, which is true in some respects. However, you will never have a complete plant grow from a leaf cutting. Cutting off a leaf and planting it cut-end down in a potting medium will keep that leaf alive, and it may even get slightly larger, but it will not produce any further leaves. It needs a piece of the stem tissue attached to build stems.
Hoya plants can be best propagated by stem cuttings. Make sure to cut a portion of the stem with at least three sets of leaves. Remove the leaves from the bottom half of the cutting and dust the stem with rooting hormone.
You can propagate your Hoya in water or soil. I find water is the most effective, and it is easier to see when your cutting has developed roots in this way. Make sure that at least one node is constantly submerged in the water or is beneath the moist soil if you go with soil propagation.
It will take two to three months for your cutting to develop roots, and it can be left in the water for even longer to develop a more substantial root system before being planted in a small pot. Keep your plant confined to a container not much larger than the plant’s root system.
Common Problems
This sturdy plant doesn’t require much maintenance, but a few issues may arise that must be dealt with.
Leaf Discoloration
Hoya leaf yellowing can stem from overwatering and repotting stress.
Leaf discoloration in Hoyas can happen for several reasons. Overwatering, stress from repotting, temperature fluctuations, and too much fertilizer are all things that can cause your Hoya’s leaves to turn yellow.
Ensure you’re not overwatering or fertilizing your plant, and keep it in a container with good drainage. When you anticipate temperature fluctuations outdoors, move your plant away from the window so that it is not affected by drastic temperature shifts.
Drooping
Droopy Hoya leaves may result from underwatering or excessive heat.
If your Hoya’s leaves are droopy, the culprit will likely be underwatering or too much heat. Feel the soil for drooping leaves; if it is dry, give your plant a solid watering. Consider moving it farther out of direct sunlight if it gets a lot of light.
Not Flowering
Optimal flower production in Hoyas demands adequate indirect light levels.
Hoya kerrii matures after about two to three years. If your plant hasn’t flowered within this time, there is a good chance that it is not getting enough sun.
Hoyas need a lot of light to produce flowers, but since they are not fans of direct light, this can be difficult to gauge. Try moving your plant to a spot where it gets a small amount of direct light in the morning to encourage blooming.
Root Rot
They are prone to root rot due to excess moisture in the substrate.
Like most succulent and epiphytic plants, hoyas are very susceptible to root rot. When the substrate remains wet, the potting materials can decay, creating an environment where the plant’s roots can rot. It can be difficult to counteract a noticeable case of root rot, but repotting can help. Remove all parts of the affected roots before potting with clean, fresh soil.
Pests
Pests may be attracted to the sweet nectar produced by the flowers.
Insects are not especially fond of Hoya kerrii, but infestations can happen. Because the plant produces a lot of sweet nectar in bloom, you may encounter pests such as aphids or mealybugs. Rinse your entire plant well with water and apply neem oil to kill off any leftover insects.
Popular Varieties
Albomarginata
This variety boasts eye-catching heart-shaped leaves with striking pale margins.
 | botanical name Hoya kerrii ‘Albomarginata’ |
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 | sun requirements Bright indirect light |
 | height 2’-3’ |
 | hardiness zones 10-12 |
Albomarginata is a very popular and somewhat costly variety with decorative leaves. As the name implies, the margins of the leaves are very light in color, pale yellow or white, while the center of the heart-shaped leaves is a much deeper shade of green. It is a flashy and noticeable plant, to be sure.
Variegata
Variegated Hoya kerrii displays softer, light green to yellow margins.
| | botanical name Hoya kerrii ‘Variegata’ |
|---|---|
| | sun requirements Bright indirect light |
| | height 2’-3’ |
| | hardiness zones 10-12 |
The variegated variety of Hoya kerrii is similar in appearance to Albomarginata, but the margins, rather than striking white, are a more subtle shade. They range from light green to yellow along the margins, with the same deep green in the center of the leaves.
Reverse Variegata
The ‘Reverse Variegata’ Hoya has lighter variegation at the center and darker green margins.
| | botanical name Hoya kerrii ‘Reverse Variegata’ |
|---|---|
| | sun requirements Bright indirect light |
| | height 2’-3’ |
| | hardiness zones 10-12 |
‘Reverse Variegata’ is similar in color to ‘Variegata’ but with one distinct difference. This somewhat rarer variety has a lighter variegation toward the center of the leaves, with darker green margins. It is quite an attractive and highly desirable variety.
Frequently Asked Questions
Hoya kerrii is a fairly common plant that can be found in most places that sell succulent plants. It is especially easy to find around Valentine’s Day, although the single-leaf plants will not produce any more leaves.
This is a slow-growing Hoya. It can take up to three years for the plant to mature and reach blooming ability.
When Hoya kerrii needs water, its leaves will curl a bit and may shrivel. If the leaves are soft and curling, give your Hoya a solid watering.
Final Thoughts
Hoya kerrii is an attractive, easy-care, flowering succulent that flourishes with neglect. Give your plant plenty of bright indirect light and water sparingly, and this plant will have a long life and produce plenty of wonderful flowers.
