Hoya carnosa ‘Mauna Loa’

Selection history of Hoya carnosa ‘Mauna Loa’

B. L. Cobia, Inc. developed ‘Mauna Loa’ from a sport of Hoya carnosa ‘Compacta’ induced by cobalt radiation. United States Plant Patent 3,054 described the cultivar in 1971. It was also marketed under the LURA-LEI and LIVING-LEI trademarks; the patent and those trademark protections have expired.

Tips for growing Hoya carnosa ‘Mauna Loa’ at home

Hang ‘Mauna Loa’ where the stems have room, or support them on a hoop. Bright indirect light suits the foliage, with protection from hot sun. Aim for 18–27°C and 40–60% relative humidity, keeping it above about 13°C and allowing airflow between the curled leaves.

Use a chunky mix in a pot with drainage holes. Water when the pot is light and the mix is nearly dry throughout, checking moisture deeper in the mix where needed. Soak the roots and drain fully. The mix dries more slowly in lower light or when growth slows.

Apply a light balanced orchid feed about every two weeks while growth continues, following the label. Pause when growth stops and flush with plain water every few months. Move up one pot size for crowded roots; replace poorly draining mix without enlarging the pot unless needed. Check whether the fresh mix contains feed and follow its guidance before feeding again.

Root a one- or two-node cutting in lightly moist propagation mix, keeping leaves clear of its surface. Use a clean blade and wear gloves, as the sap can irritate skin. Provide warmth, indirect light and humid air; a loose cover must stay off the foliage and allow ventilation. Once rooted, transfer the cutting to a small pot with drainage holes.

Help with common problems affecting Hoya carnosa ‘Mauna Loa’

• Soft, wilting growth while the mix stays wet: The established leaf curls are normal; look for a new loss of firmness. 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.
• New bleached or crisp patches on exposed leaves: 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.
• New speckling (stippling) or webbing within leaf folds: Inspect damaged leaf undersides with magnification; tapping a leaf over white paper can help locate mites. Confirm spider mites before treatment. Isolate the plant, gently rinse both leaf surfaces and let water drain. Recheck every few days and repeat rinsing while live mites remain.
• Cottony insects in the tightly curled foliage: Check concealed stem joints as well as the leaf surface. 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.

Hoya carnosa ‘Mauna Loa’ 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.

What does the name Hoya carnosa mean?

Hoya honours the English gardener Thomas Hoy. The Latin epithet carnosa means fleshy and refers to the thick leaves.

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

Carl Linnaeus the Younger first described it as Asclepias carnosa in 1782 in Supplementum Plantarum, page 170. Robert Brown later placed it in Hoya as Hoya carnosa in 1810 in Asclepiadeae, page 16.