Hoya elliptica

Meet the plant

A twining hoya with broadly elliptic, fleshy, light to olive green leaves netted with fine pale veins that run out from the midrib almost at right angles, raised a little on the surface, which is why shops call it the turtle shell hoya (NParks, Secret Garden). The net is the species' own pattern, not variegation, and it is fainter on a young leaf (Secret Garden). It was described in 1883 from Malacca (IPNI) and grows wild in Sumatra, Peninsular Malaysia and Borneo, with Thailand and the Philippines added by one database, as an epiphyte on tree trunks along rivers and streams from sea level to about 500 m (MyBIS, NParks).

That riverbank forest says most of what it wants indoors: warmth, humid air, filtered light, and a chunky mix that drains but does not stay bone dry. The hoya forums once called it a difficult but very beautiful plant (Vermont Hoyas, elliptica); NParks calls it easy to grow and one nursery calls it a fairly fast grower that is very sensitive in transit (NParks, Secret Garden). This guide says moderate: the care is ordinary hoya care, but it wants more warmth and humidity than a wax plant and sulks when it is cold or dry.

You will usually buy it as a rooted cutting of a few nodes in a 9 to 12 cm pot (Steve's Leaves, Secret Garden). What to expect in the first year: a quiet few weeks while it settles and roots, then, if it is warm and bright, a surprising amount of leaf. One grower's plant arrived in very poor shape with eight leaves and had close to thirty by the end of the summer under lights, and flowered late that summer (Vermont Hoyas, elliptica). The pairs sit close together, so each vine fills in as a dense column of leaves rather than a sparse runner. Give it a cane or small trellis to twine up from the start. In the short days it stops, and that is normal.

The ASPCA has no entry for this species. It lists the related wax plant as non-toxic to cats and dogs (ASPCA), and two shops list this one as pet safe (Secret Garden, Plant Addicts), while one botanical database lists it as toxic if eaten and says to keep it from children and pets (NParks). Until that is settled, treat it as best not chewed. The white sap is mildly poisonous and irritates sensitive skin, so wear gloves when you cut (MyBIS).

Light

Bright, filtered light: close to an east or west window, or a little back from a south one behind a sheer curtain, with no direct sun on the leaves (Steve's Leaves, Plant Addicts). In the wild it grows in semi-shade under riverside trees (NParks). For the genus, Clemson and Iowa State both say one of your brightest windows, with sun introduced gradually (Clemson HGIC, Iowa State Extension); the species-specific sources are more cautious and say to keep direct sun off, so this guide does too. A grow light works where windows are dim; the one grower who reports flowering it did so under lights (Vermont Hoyas, elliptica).

Too much sun shows as bleached or brown crispy patches, which stay (Iowa State Extension). Too little shows as thin stretched growth, pale leaves with a faint net, long bare runners and no flowers; light is the first thing to change when any hoya will not bloom (UF/IFAS Gardening Solutions, Foliage Factory).

Water

Check first. Push a dry finger into the mix to the second knuckle, and lift the pot: learn what it weighs wet and dry (Vermont Hoyas, watering, Clemson HGIC). Dry that far down and lighter than it was means it is time. Damp there means wait. The leaves help too: firm means fine, limp and soft means thirsty.

The rule: water thoroughly, until it runs out of the bottom, once the top half of the mix is dry, then let it dry to that point again (Plant Addicts, Foliage Factory). Do not water in sips (Vermont Hoyas, watering). Use room-temperature water. Sources sit close together here and all on the moist side of the genus: Steve's Leaves waters when the surface is dry to the touch, Plant Addicts when the top few centimetres are, NParks calls it moderate watering with an occasional misting, and Foliage Factory's genus rule is the top 30 to 50 percent dry in growth and 50 to 75 percent in winter, never bone dry for long (Steve's Leaves, NParks, Foliage Factory). The American extension pages say nearly dry between waterings for hoyas in general (Iowa State Extension). This guide takes the drier of the species-specific rules, the top half, because overwatering in a heavy mix is the quickest path to root decline for any hoya; it does not go to bone dry, because this is a leafy grower rather than a succulent one.

Thirsty: leaves limp, soft and hanging lower, on a dry light pot; a soak brings them back over a day or two. Overwatered: leaves yellowing or dropping while the mix is still wet, or limp leaves on wet mix, which means the roots are damaged and can no longer drink (Iowa State Extension). If the leaves say thirsty and the soil says wet, believe the soil and look at the roots.

How often that lands depends on the pot, the mix, the light and the room. In a chunky mix in a warm bright spot in summer it often comes round every week or so, and in winter roughly every ten days to two and a half weeks; no source gives a number for this species, and Vermont Hoyas finds most hoyas need nothing more often than every six days (Vermont Hoyas, watering). In winter the plant stands still and wants much less (UF/IFAS Gardening Solutions), though a pot near a radiator in dry heated air can dry faster than you expect (Vermont Hoyas, watering). It is easier to overwater when it is cool, so in a cool room err dry. Treat the numbers as a reminder to check, not as the instruction.

Soil and pot

A chunky, fast-draining, bark-led mix, because this is an epiphyte of tree trunks and its roots want air: equal parts orchid bark, peat-free compost and coarse perlite (RHS growing guide, Clemson HGIC). Secret Garden grows it in an airy epiphyte mix (Secret Garden); hoya growers go chunkier still, mostly perlite and bark with a little compost and a handful of charcoal (Vermont Hoyas, medium). Ordinary potting soil on its own stays wet too long. Mixes break down over two or three years into fine material that holds water, so refresh the mix on that rhythm even if the pot stays the same (Vermont Hoyas, medium).

The pot needs a drainage hole and should be snug. This species flowers when slightly pot-bound, and a pot too large keeps the mix wet around roots that cannot use it (Plant Addicts, Iowa State Extension). When roots fill the pot or grow out of the holes, go up one size only, 2 to 5 cm wider (Vermont Hoyas, repotting). Growers disagree on material: Vermont Hoyas prefers plastic or glazed pots because bare terracotta dries a chunky mix so fast it kills the fine outer roots, and plastic lets you judge the weight; others like terracotta for the airflow (Vermont Hoyas, repotting). For a plant that dislikes drying out, plastic in a cachepot is the safer choice. Stand a cane or small trellis in the pot early for the vine to twine up; it will also trail from a basket (Steve's Leaves, NParks).

Repot in spring, never while in bud, and only when the roots have filled the pot or the mix has gone fine and soggy; repotting too soon costs flowers (Plant Addicts, RHS growing guide). Water it in once so the fresh mix settles around the roots, then do not water again until the top half has dried; the two months after a repot are when overwatering does the most harm (Vermont Hoyas, repotting). Hold the feed for five or six weeks (RHS growing guide).

Feeding

Lightly. A balanced liquid houseplant or orchid feed at half strength every four to six weeks from spring to early autumn (Plant Addicts, Iowa State Extension). Sources disagree: the RHS feeds fortnightly in summer and monthly through winter (RHS growing guide), Vermont Hoyas feeds at most waterings in a soilless mix (Vermont Hoyas, watering), and Iowa State and Plant Addicts stop in autumn and winter when growth slows. This guide stops, and takes the weaker end. Every few months water through with plain water to wash out salts (RHS growing guide). Nothing for five or six weeks after repotting.

Flowering

Round clusters of 10 to 35 small white stars, 9 to 12 mm across, fuzzy inside the petals, with a white corona and a dark eye, held out to the side of the vine rather than hanging (MyBIS, Steve's Leaves). Sources differ on the eye: the Malaysian botanists say purple with yellow anthers, NParks says white with a pinkish tinge, and the nurseries say dark pink to red (MyBIS, NParks, Secret Garden). They are scented, most at night, and each flower lasts several days, five to seven by one account (NParks, Secret Garden). In the wild they come after rain (NParks); indoors expect summer, and put a cloth under a plant in bloom, because hoya flowers drip nectar (The Houseplant Guru).

What it takes is general hoya advice: a plant with a good length of vine, bright filtered light, warmth, a snug pot, and a steady wet-dry rhythm (Iowa State Extension, Foliage Factory). It can be quicker than most: one grower flowered a small, recovering plant in its first summer under lights (Vermont Hoyas, elliptica). On a windowsill, count in a year or two and let it surprise you.

Two things never to do. The flowers grow from short spurs that bloom again year after year, lengthening a little each time; when the flowers fall, leave the spur alone, because cutting it off is cutting off future flowers (The Houseplant Guru, UF/IFAS Gardening Solutions). Let spent flowers drop by themselves. And once buds appear, do not move, turn or change the watering until the flowers are over; a moved plant drops its buds (Iowa State Extension, RHS growing guide).

When something looks wrong

Look at the soil first, then at the warmth. Most of what follows is general hoya advice applied to a plant that minds cold and dry air.

• Limp, soft or drooping leaves. Check the mix. Dry and light: soak it through, and the leaves firm up over a day or two. Wet: the roots are damaged; let it dry well down and slide it out to look (Iowa State Extension). Sips that wet only the surface do the same as not watering (Vermont Hoyas, watering).
• Yellow leaves on wet mix. Overwatering, a pot too large, or a mix that has broken down. Stop until the top half is dry, check that water runs freely out, and repot into fresh airy mix in a snug pot if the mix is compacted (Iowa State Extension, Clemson HGIC).
• Leaves dropping soon after it arrives or is moved. This species is sensitive to days in a box, and hoyas drop leaves for cold, draughts and sudden change (Secret Garden, RHS growing guide). Keep it warm, above 16 C and off cold glass, leave it in one spot, water only when the top half is dry, and wait: bare nodes leaf again under steady care.
• No new growth for months. Often nothing is wrong: winter stops it, a cool room slows it, and a cutting roots before it leafs (Vermont Hoyas, elliptica). Warmth above 18 C, bright filtered light and a fresh mix are what speed it up; poor growth in any hoya is usually light, cold or an old compacted mix (Iowa State Extension).
• No flowers. Light, youth, pot size, warmth, cut spurs, moving, in that order. Brighter filtered light, a snug pot, every spur left on, one place, and a summer or two (Plant Addicts, Iowa State Extension).
• Buds drop before opening. The plant was moved, the watering changed, or the temperature swung (Iowa State Extension, RHS growing guide). Leave it where it is and keep the rhythm steady until it has finished.
• Bleached or brown crispy patches. Sunburn, on a plant not used to direct sun. The patches stay but the plant is fine; move it back or filter the light (Plant Addicts, Iowa State Extension).
• New leaves plain, the pale net faint. Normal on a young leaf; the net is the species' pattern and strengthens as the leaf hardens (Secret Garden). If older leaves are pale too, it wants more light.
• Thin stretched growth and long bare vines. Too little light, or simply a runner reaching out before it leafs. Move it closer to the window, wind the runner onto the cane, and do not cut it off (Iowa State Extension).
• Dark spreading spots on wet leaves. Foliage left wet without airflow, or waterlogged mix, or winter cold (Iowa State Extension, RHS growing guide). Water the mix not the leaves, let air move, remove the worst leaves, check the roots, keep it warmer.
• Mealybugs. White cottony tufts in the leaf joints: the hoya's most common pest, and NParks lists sucking insects as this species' pests (Clemson HGIC, NParks). Dab each one with a cotton bud in rubbing alcohol, wash with insecticidal soap, repeat weekly for several weeks, and keep the plant apart until clear.
• Spider mites. Pale speckling and fine webbing in dry warm air, often by winter heating (Clemson HGIC). Shower the plant, undersides included, every few days, spray with insecticidal soap or neem weekly, and raise the humidity.
• Scale. Small hard brown bumps with sticky residue (Iowa State Extension). Wipe or scrape them off, then wipe with insecticidal soap or horticultural oil and repeat.
• Black mushy base, wilting on wet mix. Root rot. Cut away every dark soft root, repot in fresh dry mix in a snug pot, water only when the top half is dry, and take cuttings of healthy vine straight away: a plant this far gone often does not recover (RHS growing guide, Clemson HGIC).

Propagation

By stem cuttings, in spring or early summer, when the plant is warm and growing. The Malaysian botanists call it easy from stem or even root cuttings, and NParks adds seed (MyBIS, NParks). Take a piece of mature but not woody vine with two or more nodes and a couple of leaves, and remove the lowest leaves; a leaf on its own may root but will never make a vine (Iowa State Extension, Vermont Hoyas, propagation). Wear gloves for the sap. Push it into moist perlite up to the first leaves, cover it to keep the air humid, and keep it warm in bright indirect light; roots usually come in four to six weeks (Vermont Hoyas, propagation). It also roots in water, in two or three weeks for hoyas in general (RHS growing guide); one grower's cutting from a damaged plant took without trouble (Vermont Hoyas, elliptica). Pot the rooted cutting into the chunky mix in a small pot and give it the same light, warmth and dry spells as its parent. A vine can also be layered: pin a length of stem to a pot of mix beside the plant and cut it free once it has rooted (RHS growing guide).