Last updated on August 25th, 2023 at 12:07 pm
Hoya retusa, also known as oak leaf hoya is a vine-like plant from the Philippines. This evergreen perennial can grow to be up to six feet long and produces clusters of yellow flowers when grown in warmer climates.
The leaves are simple ovate, glossy green on top with pale undersides that curl inward at the edges giving it its name ‘retusa’. Hoya retusa has been used for medicinal purposes since ancient times by both native Filipinos and Chinese inhabitants.
It was cultivated throughout Asian countries because of its use in traditional medicine until only recently gaining popularity outside Asia due to their beautiful foliage which makes them popular houseplants nowadays.
The propagation process for this peculiar-looking tropical plant is not too difficult due to the aerial roots that often grow from its branches. Hoya retusa can be propagated by taking a cutting, preferably with an older leaf, and planting it in moist soil which has been mixed with perlite or vermiculite.
Take care not to water too much as this will cause rot since their leaves cannot cope well with wet conditions for long periods of time.
Hoya retusa common names
The hoya retusa is also known as the “coral hoya.” The plant’s common name comes from the fact that it has a branching structure similar to coral.
How to propagate hoya retusa
Hoya retusa propagation is relatively easy and can be accomplished by using the following methods.
Air layering
To do this, you need to make a small slit into the stem near where it meets with another part of the plant’s vine from which leaves are growing – ideally between nodes for best results). Then fill with water before sealing up with damp sphagnum moss and covering.
Cuttings
This method is done by taking a stem that has healthy roots attached to it, cutting off the topmost portion so there’s an inch or two below where you want to cut, then dipping it in diluted rooting hormone powder before placing it in moist soil (or sand if root development isn’t possible) until new growth is seen; as long as temperatures remain warm enough, they should take well and grow into plants just like their parent plant.
Leaf cuttings
This method involves taking a leaf off of the plant that has grown at least one ripe orchid (floral) bud on it. The end result will be an exact clone of the parent in terms of size, type and coloration if successful; they should also have roots when planted in moist potting soil.
Rhizome cuttings
Rhizomes are underground stems that have roots attached to them. They can be planted in the ground or kept in a pot of moist soil before planting outside for best results, as they grow at an incredibly fast rate compared to other types of hoya plant propagation methods – such as rooting stalks which take years before working well enough for use outdoors).
The growth should occur outward from where you root it off; if not, give the piece more time until new growth shows up next year.
The hoya retusa will do well indoors when grown near windows at all times of the day during the winter months – often on shelves facing south or west.
Hoya retusa care
The hoya retusa is a tropical plant that needs intense sunlight to thrive. It can be found in nature at altitudes of up to 7000 feet and prefers subtropical climates, with temperatures below 80 degrees Fahrenheit during the day and above 55 degrees Fahrenheit at night. The plant also requires humid air due to its origin as an epiphytic orchid; it will not tolerate dry environments for long periods of time.
Care must be taken when handling this plant because there are many forms of rot that attack the hoya’s fronds (leaves). These include bacteria, fungi, and insects such as scale insects, mealybugs, or spider mites. Care should also be used when transplanting them so they don’t dry out.
The plant will do best if it is watered every three to five days during the summer and once a week in winter. The potting medium should be moist but not too wet, with drainage holes on the sides of the container.
As time passes, this hoya can produce rhizomes or aerial roots that grow down into containers filled with sand; these are called “rooting stalks” which will help provide stability for the plant when put outside due to high winds or storms. This process takes years before it begins working well enough for use outdoors, however, plants grown from seed typically take at least two years before they begin root development through rooting stalks as opposed to just growing their own soil-based roots (pachymorph roots).
Soil/potting mix
The hoya retusa plant does not prefer soil that is too dry but will tolerate it for a few days. It needs a moist potting mix with good drainage and should be watered every three to five days during the summer (or weekly in winter) until established in its new environment.
It can also grow well on top of cinder blocks, rocks, or even tree stumps if you want to create your own displays from natural materials; as long as they’re out of direct sunlight and there’s enough moisture available nearby then this type of growing medium will work well for them. When grown inside, such as on windowsills facing south or west, watering only during the warmer months may be necessary because plants don’t do so well with too much humidity.
There are three types of soil that can be used: peat moss combined with perlite or vermiculite (two parts peat moss mixed with one part perlite), bark chips, or clay pellets.
Watering
The hoya retusa does not react well to being watered too often, or at all if the roots are already wet. They like moist, but not soaking the soil and should be watered every three to five days during summer (or once a week in the winter) when grown outdoors; inside, they will need watering only when the soils dry out completely near windows facing south or west.
It’s important that plants have enough water for their root system to function properly before transplanting them outside as this process takes years. If you want your plant(s) transplanted sooner than later, then it is necessary for them to receive some type of artificial hydration through a spray bottle until new roots show up on rooting stalks. This can take anywhere from six months to a year, or longer if the plant is very old.
The hoya retusa does not like too much moisture around its roots in any environment and needs good drainage for healthy growth. If it has been transplanted into calcareous soil (very alkaline), then you will need to create an acidic layer by adding organic material such as pine straw, peat moss, crushed charcoal, or leaf mold, with enough depth so that water can reach down under this barrier where nutrients are stored.
It also enjoys being watered from above on occasion when grown indoors and should be misted regularly during winter; just make sure there’s no heat source involved because they do not tolerate high temperatures well at all!
Fertilizer
The hoya retusa does not need much fertilizer, but it will benefit from a light application of diluted liquid fertilizer (such as fish emulsion) every two to three months during the warmer months.
It also needs more fertilization when grown in containers or pots and should be fed with an all-purpose houseplant food at half strength once monthly during the winter (or biweekly if you feed your other plants). Fertilize less often if there is adequate natural sunlight exposure. Be wary that too much nitrogen can cause new growths to become leggy so this plant prefers moderate amounts throughout each season for best results.
Fertilizing your plant(s) with liquid fertilizer or all-purpose houseplant food at half strength once monthly during the winter (or biweekly if you feed other plants) when grown outdoors in containers or pots; indoors, they should be misted regularly to help prevent heat stress
Finally, don’t forget about dead leaves; these must be removed regularly because they hinder photosynthesis by blocking the light.
Humidity and temperature
The ideal set-up for Hoya retusa is a bright location indoors with an average temperature of 20°C and humidity levels between 40% and 50%. The roots should never be allowed to dry out, but the foliage can withstand some periods in lower light.
If you’re growing hoyas outdoors, then they will need protection from wind and sun as well as good drainage. If your plant starts wilting during this time, it means that there isn’t enough moisture present in the air surrounding it, so mist the foliage with water once a day to provide more humidity if necessary.
Hoya retusa flowers
Hoya retusa has a musky, strong-smelling fragrance that is not usually appreciated by humans. The plant emits the scent when it flowers from August to November every year in its native habitat of Vietnam and Laos. Hoya retusa blooms profusely with white or pale pink papery blooms on wiry stems. The star-shaped sepals are long and narrow while the petals are shorter and wider at their tips.
Pests and diseases
Fungal diseases can occur, and the most common of these is Botryosphaeria dieback which manifests as browning of leaf margins. It’s caused by an infection in the lower stem or root system that enters through wounds or natural openings such as lenticels on stems.
The fungus then spreads to healthy cells causing them to turn necrotic (dead). Infected plants will display symptoms including wilting, lack of vigor, and discoloration because they are not getting enough water from leaves due to their compromised vascular systems.
To prevent this, there should be adequate spacing between each plant so they have plenty of room for air circulation around all sides without touching others since it’s primarily spread via spores; remove any infected plants that show any symptoms of the disease before it has a chance to spread, and keep an eye out for wilted leaves or browning.
