Every month at Planteka, we highlight a special plant, sharing its history, essential care tips, and expert advice to help it thrive in your home. For February, we’ve chosen the charming Hoya kerrii, also known as the “Sweetheart Plant” due to its heart-shaped leaves. It’s a favourite gift for Valentine’s Day, but there’s much more to this plant than just its romantic appeal.

Before diving into everything you need to know about this plant, don’t miss January’s Plant of the Month, the Kalanchoe, a hardy succulent that blooms effortlessly. 🌸 Learn all about kalanchoe here.

History and origin of Hoya kerrii

Hoya kerrii is native to Southeast Asia, specifically Thailand, Laos, Cambodia, Vietnam, southern China, and the island of Java in Indonesia. It was first documented by the Irish botanist Arthur Francis George Kerr, who collected specimens in the Doi Suthep mountains in northern Thailand between 1910 and 1911.

Its scientific name honors Kerr, while the genus Hoya was named after the English botanist Thomas Hoy.

In the wild, this epiphytic, climbing plant grows on tree trunks, using its aerial roots to attach itself to the bark and absorb moisture and nutrients from the air. Although its growth is slow, under ideal conditions, it can reach up to 4 metres (13 feet) in height. When mature, it produces waxy, star-shaped flowers with a reddish centre and a sweet fragrance.

Characteristics of Hoya kerrii

🌱 Heart-shaped leaves – Thick, fleshy, and succulent, perfect for storing water. Some varieties have variegated leaves with yellow edges or creamy-white patches.

🐌 Slow growth – It develops at a gradual pace both indoors and outdoors.

🌸 Clusters of star-shaped flowers – Small waxy flowers with a velvety texture and a sweet scent.

🌿 Climbing plant – With proper support, it can grow as a vine in its natural habitat.

💡 Adapts well to indoor life – While it climbs trees in the wild, it thrives in pots indoors if it gets enough light.

❄️ Drought-resistant but sensitive to cold – Thanks to its succulent leaves, it can survive long periods without water, but low temperatures can severely affect it.

The single-leaf myth: why doesn’t it grow?

It’s common to find Hoya kerrii sold as a single leaf planted in a pot, especially around Valentine’s Day. However, these leaves rarely develop into a full plant.

🔍 Why does this happen?

• For a hoya to grow, the leaf must have at least one node, which is the part of the stem where roots and new shoots emerge.
• Single leaves sold as souvenirs or gifts are often cut without a node, meaning they can survive for a long time thanks to stored nutrients but will never grow or produce new stems or leaves.

💡 Tip: If you want a Hoya kerrii that actually grows and blooms, make sure to buy one with a visible stem and nodes.

How to care for a Hoya kerrii

While Hoya kerrii is a low-maintenance and hardy plant, it has specific needs to thrive. Here’s everything you need to know about its care.

Light requirements

✔️ Prefers bright, indirect light.
☀️ Can tolerate some direct sun in the morning or late afternoon.
🚫 Avoid harsh midday sun to prevent leaf burn.

💡 Tip: If the leaves turn yellow or brown, it’s getting too much light. If they look pale and growth is slow, it needs more light.

Watering and humidity

💦 Allow the soil to dry out completely between waterings.
❄️ In winter, reduce watering (once a month may be enough).
🚫 Never let the plant sit in standing water or let excess water collect in the saucer.

💡 Tip:
✔️ Wrinkled or soft leaves? It needs water.
✔️ Yellow or mushy leaves? You may be overwatering.

Soil and pot choice

To prevent excess moisture, use a well-draining soil mix:
✅ Recommended mix:

• 2 parts perlite
• 1 part orchid bark
• 1 part coconut fibre

✔️ The pot should have drainage holes to prevent water buildup.
💡 Tip: Terracotta pots help absorb excess moisture, reducing the risk of overwatering.

Temperature and humidity

🌡️ Ideal temperature: 18°C – 29°C (65°F – 85°F).
⚠️ It cannot tolerate temperatures below 10°C (50°F) or sudden temperature changes.
💦 Prefers 40%-60% humidity, though it adapts well to normal household levels.

💡 Tip: Use a humidifier or place a tray of water nearby if your environment is very dry.

How to encourage blooming

Hoya kerrii may take 5 years or more to bloom. Follow these tips to increase your chances:

✔️ Provide plenty of bright natural light.
✔️ Use a balanced fertilizer in spring and summer (twice a month).
✔️ Don’t repot too often – it blooms better when its roots are slightly root-bound.
❌ Don’t cut off old flower stalks – hoyas reuse them to bloom again.

💡 Tip: Patience is key! If your plant is healthy and gets enough light, it will eventually bloom.

How to propagate Hoya kerrii

If your plant has a stem and nodes, you can easily propagate it:

1️⃣ Cut a stem segment with at least one visible node.
2️⃣ Let the cutting dry for a few hours before planting.
3️⃣ Place the cutting in water or a light soil mix until roots develop (1-2 weeks).
4️⃣ Transfer to a pot when roots reach at least 2 cm (1 inch) long.

💡 Tip: Water propagation is often faster than soil propagation.

Common problems and solutions

🚩 Yellow leaves → Overwatering. Let the soil dry out before watering again.
🚩 Soft, wrinkled leaves → Underwatering. Give it a deep watering.
🚩 Very slow growth → Insufficient light or nutrients. Check its environment.
🚩 Pests → Mealybugs, spider mites, or aphids may occasionally appear. Inspect leaves and stems regularly.

If you have any questions about caring for your Hoya kerrii or any other plant in your collection, our Plant Doctor service is here to help. 🌱 Book a consultation with our experts and keep your plants happy and thriving.