Hoya imperialis 'Red'

Growing Hoya imperialis 'Red' at home

Give ‘Red’ a sturdy trellis with room for the long stems and large flowers. Choose bright filtered light, protected from hot direct sun, at about 18–24°C and 40–60% relative humidity. Allow gentle airflow around the foliage.

Use airy mix in a pot with drainage holes. Water when the pot feels lighter and the deeper mix remains lightly moist, then soak and drain the full root ball. As growth slows, allow the mix to become fairly dry before watering, without leaving it completely dry.

Apply a light balanced orchid feed about every two weeks during new growth, following the label. Pause when growth stops. Once roots fill the container, repot one size larger. Check the fresh mix’s label for any added fertiliser and instructions on when to resume feeding.

For propagation, take a one- or two-node cutting with a clean blade, wearing gloves because the sap can irritate skin. Remove lower leaves and root a node in lightly moist, loosely packed sphagnum in a pot with drainage holes. Keep the remaining leaves above the moss. Place the cutting somewhere warm with indirect light and humid air. Ventilate any cover and hold it off the foliage. Move to a small pot of airy mix once rooted.

Common issues with Hoya imperialis 'Red'

• Cottony insects in the large leaf joints: Confirm mealybugs beneath the wax and isolate the plant. Remove visible insects with a damp swab or tweezers. Inspect sheltered leaf joints, stems, the pot and any support weekly, removing any mealybugs you find until none remain. If mealybugs persist, use a product approved for home use against mealybugs on indoor ornamental plants in your country. Follow the label for how much to use, where to apply it, when to repeat treatment and all safety precautions.
• Leaves lose firmness while the pot is dry: Check whether the mix around the roots is dry. If the root ball is dry, water thoroughly and drain. If the leaves still wilt after watering, inspect the roots. Avoid repeated watering while the roots are still wet.
• New crisp, pale patches facing the light: Hot sun or a sudden increase in light can scorch leaves. Move the plant into bright, filtered light. If you later move it to a brighter position, introduce the stronger light gradually. Existing dry patches will not recover; retain healthy foliage.
• Soft or yellowing foliage with persistently wet mix: Persistent wetness can damage roots. Drain trapped water and inspect roots if decline continues. If you find a small amount of root rot, use a clean, disinfected tool to cut the soft roots back to firm, healthy tissue. Throw away the rotten roots and old mix. Repot in fresh, airy mix, using a clean pot just large enough for the roots that remain. The pot must have drainage holes. If decay is widespread, save only healthy stem cuttings. Discard the plant if no healthy stems remain, and disinfect your tools afterwards.

Hoya imperialis ‘Red’ is non-toxic to people and pets

• This plant is non-toxic to people, cats and dogs.
• Chewing a large amount can still cause an upset stomach.
• If a large amount is eaten and symptoms continue, contact a veterinarian or medical professional.

About the name Hoya imperialis

Hoya honours the English gardener Thomas Hoy. Imperialis means “imperial” or “majestic”, a name associated with the species’ exceptionally large flowers.

Robert Brown established the genus Hoya in 1810 in Prodromus Florae Novae Hollandiae, page 459.

John Lindley first described Hoya imperialis in 1846 in Edwards’s Botanical Register, volume 32, plate 68.