Identity & taxonomy
- Scientific name
- Hoya linearis Wall. ex D.Don
- Family
- Apocynaceae
- Genus
- Hoya
- Order
- Gentianales
- IUCN status
- Least Concern (LC)
- Wikidata
- Q3145525
- Schollia linearis (Wall. ex D.Don) Kuntze
- Pendant wax planten
- String hoyaen
- Linear hoyaen
- Hängande porslinsblommasv
- Henge-voksblomstno
- Hænge-voksblomstda
- Riippuposliinikukkafi
- Hängende Wachsblumede
Himalayas (Nepal, Bhutan, NE India, SW China — 1,500–2,500 m elevation)
How to identify it
Growth habit. Epiphytic trailing vine that produces long thin pendant stems from a basal crown. Each stem trails downward and produces leaves at internodes of 2–4 cm. Stems do not climb readily — Hoya linearis is grown as a hanging plant rather than a trellis-trained one. Growth rate is moderate; established plants add 20–40 cm of stem length per year. Old peduncles (the bumpy stalks left after flowers fade) re-bloom annually for years if left intact.
Leaves. Linear-cylindrical to terete leaves 3–5 cm long and just 2–4 mm wide, soft and slightly fleshy with a covering of fine pale hairs (pubescence) — entirely different from the thick waxy hairless leaves typical of most cultivated hoyas. Leaves are pale to medium green, slightly grooved on the upper surface. They are arranged in pairs along the trailing stems at intervals of 2–4 cm. The texture is soft to the touch — closer to a gymnocalycium or sedum than to other hoyas.
Flowers. Spherical umbels of 8–15 small five-pointed star-shaped flowers. Each flower is 6–10 mm across, pure white or white with a pinkish blush, and has a small five-pointed central corona — typical hoya 'wax flower' anatomy at miniature scale. Strongly fragrant in the evening with a sweet lemony-vanilla scent. Blooms in late summer and autumn (August–November) on mature plants 3+ years old. Each umbel lasts 1–2 weeks.
- Thin needle-cylindrical leaves 3–5 cm × 2–4 mm — unlike any other cultivated hoya.
- Soft pubescent (hair-fringed) leaf texture, not waxy.
- Strictly pendant trailing habit — does not climb readily.
- Pale green leaf colour with slightly grooved upper surface.
- Late summer/autumn fragrant white star-flower umbels.
Commonly confused with
Grass-leaved hoya
Similar pendant habit and thin leaves but Hoya retusa leaves are flat-bladed and notched at the tip (retuse), not cylindrical needles. Same fragrant white flowers.
Few-flowered hoya
Thin-leaved trailing hoya with broader flat leaves than linearis and very large solitary flowers (3–5 cm) instead of star-clusters. Different overall silhouette.
String of hearts
Trailing succulent in same family (Apocynaceae) but with heart-shaped grey-and-purple leaves. Completely different leaf shape; same hanging-plant aesthetic and similar care.
String of pearls
Spherical bead-like leaves on a trailing stem; a true succulent unrelated to Hoya. Very different leaf shape and texture but similar hanging-plant aesthetic.
Care
Light
Bright indirect; 1–2 hours of gentle direct sun encourages blooms.
An east window, a north-bright window, or hung 1.5 m back from a south or west window with a sheer curtain. Hoya linearis is a montane cloud-forest epiphyte — it gets bright filtered light in nature, not full sun. Direct unfiltered noon sun bleaches and burns the soft leaves. Below 7,000 lux the plant survives but rarely flowers.
Seasonal: Nordic latitudes above 55°N: dim winters significantly slow growth and may delay flowering by a season. The brightest available indirect spot from October–March is required to keep the plant in good condition.
Water
Top half of pot dries — every 7–10 days.
Hoya linearis needs MORE frequent watering than most hoyas because the thin needle-shaped leaves and shallow epiphytic root system store less water. Let the top half of the pot dry between waterings, then water thoroughly until runoff. Do not let the plant fully dry out — leaves shrivel within days, and recovery from full desiccation is slow. Conversely, sustained wetness rots the basal stem within weeks.
Seasonal: Reduce frequency by about a third in winter when growth slows.
Soil
Very chunky free-draining epiphytic mix; never plain potting compost.
Two parts orchid bark, one part perlite, one part fine bark/coir mix, plus a handful of horticultural charcoal. Hoya linearis is epiphytic and resents standard potting compost — it suffocates the shallow roots and rots the basal stem. The mix should look airy enough to see through; water should drain straight through the pot in seconds.
Humidity
60–70 %; tolerates 50 % grudgingly.
Hoya linearis is one of the most humidity-demanding hoyas. Native cloud-forest habitat sits at 60–95 % humidity year-round. Indoor air below 50 % causes leaf shrivel and tip browning within weeks. Run a humidifier nearby through heating season; pebble trays and grouped plants help marginally.
Temperature
13–24 °C; prefers cooler than other hoyas.
Unlike lowland tropical hoyas (carnosa, kerrii, pubicalyx), Hoya linearis prefers cooler temperatures. Native Himalayan habitat at 1,500–2,500 m has cool nights even in summer and frost-free but cold winters. A cool 10–13 °C winter rest of 6–8 weeks dramatically improves flowering. Avoid sustained heat above 28 °C combined with dry air.
Fertilizer
Half-strength balanced feed monthly in growing season.
Half-strength balanced NPK monthly April–September. Switch to a high-potassium bloom feed for 6 weeks before expected flowering (July–August) to encourage umbel production. Skip feeding October–March entirely. Hoyas are sensitive to over-fertilising; symptoms include soft growth and pest susceptibility.
Pruning
Trim dead strands; NEVER cut spent flower peduncles.
Trim out fully dried or damaged strands at the basal crown. Do not cut healthy strands back to encourage branching — Hoya linearis branches poorly and the cuts often fail to re-shoot. CRITICAL: never cut off the bumpy peduncles left after flowers fade. Hoyas re-bloom annually from the same peduncle for years; cutting them off resets the flowering clock.
Repotting
Every 3 years OR when basal crown lifts visibly.
Move up by ONE pot size only. Hoya linearis flowers more reliably when slightly pot-bound and resents over-potting. Spring is the best time. Use a free-draining epiphytic mix; standard houseplant compost rots the roots within months.
Stem-tip cuttings
moderate~6–10 weeks in damp sphagnum or perliteCut a 10–15 cm strand with at least 3–4 leaf pairs and let cut surface callus for 24 hours. Root in damp sphagnum moss or perlite at 22–25 °C with 70 %+ humidity (covered container). Roots emerge within 6–10 weeks. Pot into chunky epiphytic mix once roots are 3–5 cm long. Slower-rooting than Hoya carnosa or kerrii — patience required.
Air-layering on long strands
moderate~8–12 weeksWound a node on a healthy long strand, wrap with damp sphagnum and plastic, and wait for roots to form before cutting and potting. Useful for propagating without sacrificing the apex. Less efficient than tip cuttings for a small home grower; more useful for nursery propagation.
Common problems
Leaves shrivelling rapidly
Symptom
Needle leaves go soft and wrinkled within days; plant looks 'thinner'.
Cause
Two opposite causes that need different fixes: (1) severe underwatering, especially after a dry holiday — the plant has no water reserves to shrivel from. (2) Root or basal-stem rot from sustained wetness — the plant cannot draw water through dead roots, so leaves shrivel despite wet soil.
Fix
Check the soil 5 cm down. If bone-dry, water thoroughly and consider bottom-watering by sitting the pot in a shallow tray of room-temperature water for 30 minutes. If soil is wet, unpot and inspect the basal crown for blackening or softness — if rotted, take healthy stem-tip cuttings as a salvage and discard the parent.
Plant has not flowered in years
Symptom
Healthy strands but no umbels appearing.
Cause
Plant too young (3+ years from cutting before first bloom), light too low, missing winter cool rest, peduncles cut off in past pruning, or pot too big.
Fix
Move to brightest available indirect light, ideally with 1–2 hours morning direct sun. Provide 10–13 °C cool winter rest for 6–8 weeks. Keep slightly pot-bound. NEVER cut off peduncles. Switch to high-potassium bloom feed in mid-summer. Patience: many hoyas need 4–5 years before their first flowering.
Basal stem turning black
Symptom
The crown where strands meet the soil goes soft and black; whole strands flop over.
Cause
Basal-stem rot from waterlogged soil — the most common Hoya linearis killer.
Fix
Unpot immediately. If most of the crown is rotted, take all healthy stem-tip cuttings and root them; the parent plant will not recover. Use chunky epiphytic mix going forward and water only when the top half of the pot is dry.
White cottony tufts at leaf bases
Symptom
Cottony white waxy tufts where leaves attach to the stem.
Cause
Mealybugs sheltering at leaf bases — a favourite Hoya pest.
Fix
Dab each visible mealy with a cotton bud dipped in 70 % isopropyl alcohol. Repeat weekly for 4–6 weeks because eggs hatch in waves. Heavy infestations may warrant systemic insecticide (acetamiprid drench).
Brown leaf tips and yellowing
Symptom
Tips of needle leaves go brown and crispy; older leaves yellow and drop.
Cause
Low humidity below 50 %, or fluoride/salt build-up from tap water.
Fix
Run a humidifier nearby aiming for 60 %+. Switch to rainwater, distilled water, or filtered water. Flush soil with 3× pot volume of rainwater. Trim brown tips with sharp scissors; new growth should emerge clean within 6–8 weeks.
- Mealybugs at leaf bases and crown
- Spider mites in dry winter air
- Scale insects on stems
- Basal-stem rot from overwatering
- Botrytis grey mould in stagnant cool conditions
Toxicity & safety
No reported toxicity in humans. The genus Hoya has no documented poisoning cases in the medical literature.
Hoya linearis — North Carolina Extension Gardener Plant ToolboxHoya is not listed in ASPCA's toxic plant database. Generally considered safe for cats; no documented poisoning cases. Note that the milky sap typical of Apocynaceae can occasionally cause mild GI upset if ingested in quantity.
ASPCA Toxic and Non-Toxic Plants — Hoya not listed in toxic databaseHoya is not listed in ASPCA's toxic plant database. Generally considered safe for dogs.
ASPCA Toxic and Non-Toxic Plants — Hoya not listed in toxic databaseWhy Hoya linearis is the hoya for cool Nordic apartments
Most popular hoyas — carnosa, kerrii, pubicalyx, australis — come from lowland tropical Southeast Asia. They want temperatures in the high 20s, high humidity year-round, and sulk in cool rooms below 18 °C. Hoya linearis is the outlier. Native to Himalayan cloud forest at 1,500–2,500 m elevation, it experiences cool nights even in summer and a chilly but frost-free winter rest, and prefers bright indirect light over the deep filtered shade of lowland rainforest.
This makes Hoya linearis paradoxically one of the BEST hoyas for the cooler ends of European apartments — north-facing rooms in winter, draughty hallways, slightly cooler bedrooms. It actively flowers more reliably with a 10–13 °C winter rest, which most apartments incidentally provide if you leave a plant near an inner window during a cold snap. Conversely, hot stuffy living rooms with central heating cranked to 25 °C suit it badly.
Of the cultivated hoyas, only Hoya linearis and Hoya retusa share this 'cooler is better' character. If you've struggled to flower a Hoya carnosa in a cool flat, Hoya linearis is the easier alternative — same plant family, same fragrant white star-flowers, same 'set the peduncles, never cut them' rule, but suited to the conditions you actually have.
Why you should never cut a hoya peduncle
All hoyas, including Hoya linearis, share a peculiar flowering biology that catches new owners out: they flower from persistent woody stalks called peduncles that emerge once and then re-bloom every year for the rest of the plant's life. After the flower umbel fades and drops, the peduncle stays — a small bumpy 1–3 cm stub on the stem. To an inexperienced eye it looks dead and tidy-minded gardeners often snip them off.
This is the single most common reason hoyas mysteriously stop flowering. The peduncle is alive and dormant; it produces a fresh umbel from the same point the next year, and the year after, and the year after that, often for a decade or more. A mature Hoya linearis with 8–10 peduncles can produce a fragrant flower display every summer with no further effort.
Cutting a peduncle off doesn't just lose this year's bloom — it loses ALL future blooms from that point. The plant has to grow new strands and produce new peduncles before it can flower again, which can take 2–3 years. The rule with hoyas is simple and absolute: leave the bumpy stalks alone, even if they look spent or untidy.
Hoya linearis was first described by Nathaniel Wallich in 1828 from collections in the Khasi Hills of north-east India, but it remained extremely rare in cultivation for almost 150 years because it requires cooler conditions than the typical tropical greenhouse provided. The species exploded into popularity in Western houseplant culture in the early 2020s as the 'string-of-something' aesthetic took off and growers learned that linearis is the easier-to-flower thin-leaved hoya — flowering at 3–4 years from cutting, where many other hoyas need 5+ years. Its native habitat at 1,500–2,500 m elevation in Himalayan cloud forest is exactly the cool-and-bright combination that's hard to provide in a tropical greenhouse but easy to provide in a temperate apartment.
Frequently asked · 5
Is Hoya linearis safe for cats and dogs?+
Yes — generally. Hoya is not listed in the ASPCA's toxic plant database, and no poisoning cases are documented in the medical literature. The milky sap typical of Apocynaceae can occasionally cause mild GI upset if ingested in quantity, but Hoya is widely regarded as a pet-safe houseplant family. It is one of the better options for cat households among trailing plants.
Why are my Hoya linearis leaves shrivelling?+
Two opposite causes that need different fixes. (1) Severe underwatering — the thin needle leaves have less water reserves than thick hoya leaves and shrivel within days of being too dry. (2) Basal-stem rot from sustained wetness — leaves can't draw water through dead roots and shrivel despite wet soil. Check the soil 5 cm down: bone-dry means water thoroughly; wet means unpot and inspect the basal crown for rot.
How long until Hoya linearis flowers?+
Typically 3–4 years from a rooted cutting under good conditions. Flowering requires the plant to reach maturity, bright indirect light, a cool winter rest at 10–13 °C, and uncut peduncles. Once flowering, mature plants bloom annually from late summer through autumn with fragrant white star-shaped umbels. Hoya linearis is one of the easier-to-flower thin-leaved hoyas.
Why is my Hoya linearis dropping leaves?+
Most often basal-stem rot from waterlogged soil — the leading killer of this species. Less often: extreme underwatering, sudden cold draught, or pest infestation (mealybugs at the crown). Check the basal crown for softness or blackening. If rotted, take all healthy stem-tip cuttings and root them; the parent plant will not recover. Switch to chunky epiphytic mix going forward.
Can I cut my Hoya linearis to make it bushier?+
Generally no. Hoya linearis branches poorly and cuts often fail to re-shoot — the natural growth pattern is long pendant strands rather than a bushy form. The species looks best left to trail. If a strand gets damaged, trim it out at the base. NEVER cut off the bumpy peduncles where flowers have faded; they re-bloom annually for years.