HOYA CULTIVATION IN THE GARDENER’S POINT OF VIEW

            Hoyas are the next “big thing” when it comes to plant collections after orchids.  As orchids get more and more demystified and readily available to the greater masses, plant collectors shy away from them since these kinds of people want to have a unique array of exotic and hard-to-get plants.  There are also mounting complaints about the complexities of taking care of them and flowering them gets harder as a result of climate change.  Hoyas, on the other hand, tends to go the other way and is on its way to greater popularity in despite of a very slow start.

This is my Hoya jungle!

            As succulents and semi-succulent plants, Hoyas are better equipped in the humid and drier conditions of any bustling metropolis here in the Philippines particularly in the NCR where the bulk of plant collectors reside.  A twist this genus has is its tolerance and preference for shadier conditions unlike the majority of succulents.  One setback however that most people complain about this highly adaptable family is their small flowers.  Unlike the Orchidaceae family that has a wide availability of flower sizes from giants like those of Grammatophyllum speciosum,  Paphiopedilum philippinensis, and the various Cattleya species, the largest Hoya flowers are only around two to three inches in diameter (Hoya imperialis, Hoya archboldiana, Hoya lauterbachii, etc.).

        

Hoya kerrii is one of the most succulent Hoya species there is. It hails from Thailand and Laos. The spur can withhold the development of the flowers until the brightest and hottest days of summer sets in!

    Nevertheless, what Hoya flowers lack in size, they make up in floriferousness, fragrance, faithfulness (with some species only resting for some one or two weeks then blooms again), and ease of cultivation.  This paper will concentrate on the latter topic as this is the most detrimental in having a robust plant that would continuously bear flowers and even fruits.  First, the author categorised the kinds of gardeners he has noted and observed.

MVP’S CLASSIFICATION OF GARDENERS

            There are three kinds of gardeners that the author has noted from years of mingling with them.  First are the common gardeners, then the average gardeners, and last but not the least the serious gardeners.

The common gardeners are plant lovers that do not distinguish as to what plant is to be taken care of.  As long as the plant is beautiful, these will likely be added as part of the collection.  The common gardeners are also the ones who are likely not to buy or acquire special gardening tools, pots, media, etc. and will rather use what is just available around no matter if these are substandard or unsuitable to the plant.  They merely appreciate the beauty of plants or any good thing that could be derived from them without paying attention to maintaining their good and healthy growth. They could also be called “come-what-may” gardeners.

            Next are the average gardeners who seem to be plant lovers that have more knowledge about plants, collects certain types of plants according to the category they have established for themselves and who will buy gardening materials if it is only highly necessary.  They tend to keep plants that they can easily care for and concentrate on them.  Some of them are serious enough to attend seminars about plants but it is up to their whim whether to use the knowledge they have acquired or not.

            Finally, the serious gardeners who are almost pseudo-botanists or pseudo-horticulturists that possess extensive knowledge about plants, have a lot of reference materials on them, are epicureans and connoisseurs when it comes to the plants they are collecting or going to collect, and will likely buy gardening materials to provide the best care for their plants.  These people frequent plant exhibits because they thirst for more knowledge in order to sharpen their cultivation skills.  They have some of the rarest and most expensive plants in their collections including rare fruits, novel medicinal or food items, etc. 

I find the cultivation of Hoya campanulata, a native of Sabah, Malaysia, somewhat bizarre: it hates improper watering, it hates desiccation, it likes hidden among bigger plants where it can twine its tendrils, and it loves the rain! The fragrance is reminiscent of Cymbopogon nardus or the Citronella plant. 

            These three categories of gardeners often meet and mingle during exhibit seasons of the various plant lovers’ societies or in online groups such as the  Horticultural Society of the Philippines (yearly every January), the Philippine Orchid Society (yearly every February and September), Panagbenga (yearly every February in Baguio City), Los Baños Horticultural Society Exhibit (yearly every March and October within the UPLB campus), Philippine Alliance of Bonsai and Suiseki, Inc. (every May), Kadayawan (yearly every August in Davao City), Cacti & Succulent Society of the Philippines, Inc. (every two to three years between November and December), Flora Filipina (the Philippines’ largest international plant exhibition held every three years),  Bonsai Society (sporadic), CP Lovers Forum, and even online groups like hoya_philippines and the Philippine Hoya Conservation Group both in Facebook.  The latter two groups offer absolutely free memberships and regular daily communications among the members.

            Let us now be acquainted with some serious gardeners who have grown Hoyas seriously and how the author of this manuscript personally witnessed their cultivation techniques.

Before I have my Tengoku no Kokoro-Hagetalka under construction, this is how a Hoya jungle would look like hahaha!

            ARCHITECT WENDY REGALADO’S “ART MEETS PLANT” STYLE: Ms. Wendy Regalado was a two-time consecutive former president of the Philippine Horticulture Society who took taking care of Hoyas seriously.  She lives in Antipolo, Rizal Province which is some 200 to 500 m above sea level with a garden having various plants both native and foreign. 

            Here she dedicated a semi-shaded and cool area of her garden to house her Hoya collections.  As an architect, she used her skills to artistically plant her Hoyas in innovative ways such as in hanging plastic bags, in screen wire frames, and in pots with a lot of holes.  During the opening of the Cacti & Succulent Society of the Philippines, Inc. Country Fair & Exhibit last October 17, 2012, Ms. Wendy disclosed to the author of this manuscript that she uses pure coco fibre or coconut husk as medium of her plants and that it works great for her.

            This might be caused by the rainy climate in Antipolo and its geographic location. Coconut husk and coconut fibre tends to dry out quickly and are highly suitable to mostly rainy areas.

            SIR DANILO ARGUSON TIU’S “TAMPITAN CONNECTION” STYLE: Sir Danny is an agriculturist by profession and the protégé of the Philippines’ pioneer orchid exponent Dr. Helen L. Valmayor.  He is Dr. Valmayor’s technical assistant when she made the orchid bible of the Philippines entitled “Orchidiana Philippiniana” which is still unsurpassed even by today’s standards.  Sir Danny is also the author of the highly acclaimed book “Deciphering the Scriptures in Philippine Grammatophyllum” which made him a recipient of the highly coveted Best Taxonomist and Horticulurist award by the University of the Philippines.

            He has introduced a lot of plant genera and species to the general public through his various publications particularly in The Philippine Gardener (the official magazine of the former United Garden Clubs of the Philippines) among which are Pitcher Plants in the Philippines (October to December 1981 issue) and Hoya of the Philippines (January to March 1982 issue). Both these articles are classics since they are among the earliest treatises on these genera published locally and are very comprehensive with a taxonomic approach intended to be understandable by the common “tao”.

            Sir Danny Tiu introduced me to his cultivation method once I met him at the Philippine Nuclear Research Institute when he handed an unidentified Hoya species to be identified.  The author of the manuscript learnt a lot of useful Hoya information from him.

Mandaluyong City is at the very heart of the National Capital Region and is somewhat higher than the other surrounding cities since it has a solid foundation being once a hilly kingdom.  It is also a city of high rise buildings and houses as the total land area is only more than 11 square kilometers.  This attribute is extremely useful if the plants are situated higher up the houses or buildings as ventilation and bright light is better with greater heights.

His newest cultivation method when it comes to Hoyas and other epiphytes is making use of bamboo poles cut around a foot high hollowing the central parts but leaving the top and bottom parts intact.  The hollowed parts are filled with coconut fibre to hold the Hoya plant firmly in place and the bottom part is retained to hold a small amount of water as an insurance against hot and dry periods and also if the gardeners are out-of-town and could not tend to their plants for a certain period of time.  These “tampitan” as Sir Dan calls his invention, will have serve its purpose in a year or two but it has prepared the Hoya plant very well for its next pot.  What’s good in “tampitan” is that they don’t occupy too much space in the garden and are very light and portable.

            EDWARD AGDEPPA’S “STOCKING & FORMULA MISTING” STYLE : Ed is the hoya_philippines moderator and founder of the Facebook group Philippine Hoya Conservation Group.  He lives in North Olympus, Fairview, Quezon City.  According to Wikipaedia, this part of Quezon City has a monsoonal climate that is why it rains more often in that area compared to other more tropical areas of the National Capital Region. 

            Ed does not take away or transfer his newly bought Hoyas if they are already established in their pots.  Instead, he finds a suitable place where to put the potted Hoyas in his garden.  Majority of his plants are situated in the plot of land in front of his own house which he bought and made into a jungle-like garden. Under the shade of the trees in this garden are his various Hoyas which are mostly hanging. However, he just ties his Hoya cuttings to the trunks and twigs of trees around his house and garden mostly without any medium but with preference to stockings as tying material since it could retain some moisture according to Ed.

            Newly acquired cuttings are placed by Ed in resealable plastic bags sprayed with his self-invented formulated spray before resealing them again.  Some Hoyas do respond quickly to this method and in just a week bear roots readily while other Hoyas do not respond that fast and some die.  The fatality might be caused by prolonged sealing in the plastic bags and too much spraying.  He still has to address the question whether it is better to grow cuttings with intact leaves, half-cut leaves, or no leaves at all.

            Ed has also successfully germinated Hoya seeds which he has gathered from various sources using table napkins and vermisoil as media and plastic containers with lids as “seed growing chambers”.   The formulated spray is somewhat effective but too much use can also be fatal to plants as I have witnessed it personally. 

            INSTITUTE OF PLANT BREEDING, UPLB “THE IPB WAY” STYLE: Being the leading agricultural school in the country, UPLB has the most complete facilities, materials, technology, knowledge, and communication network that they could use in their cultivation of plants and Hoyas in that particular matter.  Dr. Monina Siar, before her untimely death last 2011, was the proclaimed successor of the world’s leading Hoya exponent Dale Kloppenburg. 

Kloppenburg is the author of the book entitled Philippine Hoyas, which is considered to be the bible of Philippine Hoyas and is still unsurpassed by any publication regarding the genus Hoya throughout the world in the profundity of how it discussed each individual Hoya species known during the time of its publication. 

IPB has three greenhouses that contain their Hoya collections.  Today the Hoya plants are arranged alphabetically and almost all of them are grown in hanging pots. Some propagation is placed atop iron steel planters. Here they use pure fern chips as potting medium.  Jenn Carandang, third in line of the Hoya researchers after Dr. Siar and Ma’am Babes Guevarra, told me that they will soon shift to coco products (coco chip, coco husks, coco fibre, etc.) as medium for their Hoyas; this is better since harvesting fern chips or fern slabs kills tree ferns and contributes to their extinction.  This is the only place that has a covered greenhouse dedicated to Hoyas I have seen so far.  The white sheet roofing of fiberglass or polycarbonate material has a layer of dyna net to thwart the excessive heat of the sun but allow the brightness to penetrate within.  The spacious greenhouses also encourage good ventilation and hanging the Hoyas ascertain that crawling or any terrestrial insects won’t wreak havoc to the plants. 

The Institute of Plant Breeding, just like the whole UPLB grounds has mountains as its background foremost among these is Mt. Putho, it has a very good natural environment far from pollution and the area is rainy which is the case of almost the whole province of Laguna.

ARCHITECT PATRICK GOZON’S “KNOT AND PLANT” STYLE: Architect Patrick recently took up his masteral degree in Landscape Architecture in UP Diliman, Q.C. and one of the original members of the Philippine Native Plants Conservation Society, Inc. (PNPCSI).  Long before he took up his M.S. in Landscape Architecture, he has converted the author of the manuscript and others into Hoya lovers being a member of the online group cactus_philippines where they first virtually met and got acquainted with one another.  He has one of the finest gene pools of Hoyas among the NCR collectors.  Residing at Banawe St., Quezon City, his garden is located at the rooftop of their three storey house.  The garden has an open air with several areas kept shaded for group of plants needing solace from the sun’s heat.  He generally takes care and collects native plants which is one characteristic he imparted to the author. 

In one corner of his garden, he has a roofed area dedicated to Hoyas.  Everywhere within this place are Hoya species twining and climbing wherever they can.  He uses coconut husks and coconut fibre for some species, soil in hanging pots to others and to pots sitting in the ground or in planters, or combinations of these media.  The place is kept cool and moist by everyday watering and due to its proximity to his water plants collections. 

Whenever he takes a cutting of his Hoyas, he ascertains that the length of the stem is sufficient enough to form a knot. The other end is planted to the medium and the other end is where the new growth will sprout.  Sometimes both ends are planted to the medium.

MVP’S “VARIABILITY & DIVERSITY” STYLE:  MVP or Nolie or Kenneth (for his Facebook friends) Perez de Tagle is a member of the Cacti & Succulent Society of the Philippines, Inc., CP Lovers Forum, hoya_philippines, Philippine Hoya Conservation Group, creator of Marvelous Vibrant Plants and Weird & Carnivorous Plants (both are Facebook pages), as well as a blogger of nature and environmentally-related articles.  He started growing Hoyas way back in 1996 when his Filipino-German couple friends living near their Binangonan, Rizal summer house introduced him to this genus of plants.  At first he found this genus of plants unappealing but the former persuaded him by giving him one of their Hoyas.

Binangonan, Rizal is a cool, well-ventilated and dry place most of the year and even cacti and other succulents find it hard to thrive there without some watering once a week.  As is common with most provinces in the country, it is still largely free of pollution.  Another factor the place has is its proximity to the largest freshwater lake in the Philippines-the Laguna Lake that also affects the climate to some extent.  There are still existing large forests in the province and many Hoyas and orchid species have been discovered here.  Limestone forests predominate. 

Nolie/Kenneth planted this Hoya in a noodle cup using ordinary soil and placed it in a shadier part of his garden.  It was a variegated Hoya which according to Dr. Madulid’s book, “A Pictorial Cyclopaedia of Philippine Ornamental Plants” is scientifically named Hoya carnosa ‘Silver Princess’.  After four years this plant bore cinnamon-scented flowers! He did not water the plant regularly nor brought it to a brighter corner of the garden.  He just let it thrive on its own. It then grew into a vine some 15 feet in length twining in the window grill.  Nolie noticed that variegated plants grow and flower slower by studying his Hoya carnosa very well.

In 2008, in one of the monthly meetings of the Cactus and Succulent Society of the Philippines (CSSPI), Hoya became a hot topic and that was the beginning of Nolie’s/Kenneth's love affair with Hoyas simultaneously the meeting paved the way for the start of the Hoya craze in Manila. He has participated in expeditions to examine areas where Hoyas naturally grow and carried his own Hoya cultivation experiments and came up with what he calls “MVP’s Variability & Diversity Style”. 

“MVP’s Variability & Diversity Style” is a method that according to Nolie/Kenneth makes use of various kinds of media in growing Hoyas and not adhering to only one universal potting medium.  Among these media are coco coir, coco dust, coco fibre, coco cubes, coco husk, hydrocorn/hydroball, pumice (which according to Jenn Carandang is a luxury to be used as potting medium for Hoyas!), old fern chips he has acquired long before its ban, and even ordinary soil.

Since he found his Tengoku no Kokoro-Kyujo (Nolie’s/Kenneth's garden in Binangonan) too dry for his Hoya plants, he started transferring them to his Tengoku no Kokoro-Hagetaka (his Mandaluyong City garden) situated in the third floor of their house some 22 feet above ground where they benefit from being semi-shaded and regularly tended for.  He also lets his Hoyas twine whenever they want to.  Some Hoyas have even already attached their roots to the garden walls! 

Nolie/Kenneth also prefers hanging his Hoyas rather than letting them sit in planters or in any corner of the Tengoku no Kokoro as he believes through this way the plants are well ventilated and any excess water will not cause root rots or encourage any water-borne diseases. 

He constantly battles with aphids and mealy bugs which are the most common pests of Hoyas by spraying them with ordinary water and killing them by hand.  Albeit the numerous Hoyas Nolie/Kenneth has, being vigilant every now and then to check on these little monster-suckers ensures they don’t grow to “plague-like” proportions.
Very recently, when Nolie/Kenneth was making his thesis entitled "Nepenthes Cultivation in Lowland Metropolis", he discovered a wonderful surprise while studying his pitcher plants: Nepenthes or Old World pitcher plants love consuming tonnes of ants for their nutrient requirements and the dwindling ant population in his Tengoku no Kokoro made aphids, mealy bugs, and other harmful insects almost non-existent in his garden if not on a very controllable population!

PONCHIT PONCE ENRILE’S “WAY OF FLOWERING” STYLE:  The author found a highly useful cultivation method which was written by a veteran plant lover in the person of Ponchit Ponce Enrile and published in The Philippine Gardener July-September 1984 issue and here are the salient points which I have translated from the original Filipino:

  Do not let the roots grow rampantly as this will cause slow flowering. 

   In Ponchit’s own experience, squeezing the roots in a small pot would trigger faster flowering.

  Ponchit transfers his Hoya plants in a bigger container after a year and he advised that the permanent pot for Hoyas is a size eight pot and he replaces the medium every five years.

  Most Hoyas must be kept away from the intense heat of the sun.

  Don’t let Hoyas dry for prolonged periods and Hoyas also don’t want a soaking wet medium.

  Hoyas grow slowly during its first year and it will not bear flowers if the cuttings are too short.

HOYAS’ SECRET TO FLORIFEROUSNESS:

  Cut a one metre long vine with a spur where the plant will flower.

  Remove the leaves near the base of the cut portion, tie into a knot, and bury the knot under the medium.

UNIVERSAL RULES & CONCEPTS: 

  NEVER cut the spur or from where the flowers of the Hoya plant were first borne as this will bear the succeeding flowers.  Botanically this is called the PEDICEL which is defined as “the flower-bearing structure or stem that generally arises from the nodes on the portion of the plant’s stem between the paired leaves” (Philippine Hoya book by Dale Kloppenburg).

  Although many Hoya species are succulents or semi-succulents, they are better watered everyday but must be monitored that they don’t get soaked even for a day.

  Those Hoya grown in coconut husk and hydrocorn/hydroball will dry out faster than those in other media and will need more watering.

  Keep Hoyas in partial shade as they disdain direct and full sunlight but putting them in shadier areas will not encourage flowering either.

  Dr. Monina Siar once stated in one of her messages to the online group hoya_philippines that, “there is no need to study or do pollination of Hoyas as they are easily propagated through stem cuttings”.

  Aphids and mealy bugs are the commonest Hoya pests and they usually find the minute sweet watery exudes of the growing points highly irresistible and you'll find them clustered there.  It is better to pinch to death each one of them if they are few or if they cluster in areas very vulnerable to pinching, squirt water from a spray gun. Some people use a solution of diluted soap in water and this is environmentally sounder than using man-made pesticides or insecticides.  After quite sometime these creatures will return so be vigilant and do these methods every time they appear.  Real success is not in eradicating them but rather controlling them from reaching plague proportions and killing your Hoyas.

  A difficult species to grow for one gardener might be the easiest to another gardener.  This is caused by the microclimate in one’s area and the gardener’s extent of ability in cultivating species which are deemed notoriously stubborn in cultivation.

  “The color (of Hoya flowers) will vary depending on the weather conditions, mainly temperature under which the flower develops.  This effects the acidity within the cells, which in turn effects the color.”-Dale Kloppenburg, ‘Philippine Hoya Book’.

  An excerpt from the article entitled, “The Amazing World of Hoyas” by Rita T. dela Cruz, states that, “Another (method of propagation) is by seeds. It is advised that only freshly harvested seeds are used for propagating since these seem to germinate better. Germination rate is high if sown in a mixture of coir dust and quarry sand. Once the seedlings start to develop true leaves, repot and plant out separately.”

  The author found this advise useful from http://www.succulent-plant.com/families/ asclepiadaceae.html and has been using this for several years and not only on his Hoyas but also on his other plants as well. Many control aphids, mealy bugs, red spider mites and scales with plain old rubbing alcohol, spraying it on the plants right from the bottle. Others dilute it with water and add soap or sticker spreaders to it. Some say you should wash the alcohol off after it has done its job, but it isn't necessary. It does no harm as long as the sun doesn't hit the plants while they are still wet - it is no different than plain water in that respect. Some use insecticidal soaps but this it was found that the use of alcohol and insecticidal soaps to be worthless, except that alcohol applied to a swab, used to wipe the insects off does a pretty good job but this is extremely impractical in a large collection and could become a full time job. 

  RESEARCH, EXPERIMENT, OBSERVE!!!

Hoya lacunosa, indigenous to Malaysia and The Philippines, is one of the more cold-loving species of the genus. It grows poorly during the hot Philippine summer season so better keep this one in a cooler environment.  The flowers are small but the fragrance makes up for it!

SOME CULTIVATION TIPS ON HOYA SPECIES (as experienced by MVP):

1.     Hoya buotii- planted as a cutting in fern chips and placed in partial shade, it bore flowers just after two months! This is the fastest flowering Hoya in the author’s experience since it flowered after only two months after he planted it.  It has a very feminine night fragrance.  Flowers seem to abort during the rainy season or infestation from aphids and mealy bugs.  Hoya buotii is the author’s most “diligent” flowering Hoya species as well as the one that sends multiple spurs at any time; however, flowering aborts if it comes in contact even with a small amount of water. 

2.     Hoya halconensis- better if grown in soil but hates to get dried for an extended period of time. Although this is a close relative of Hoya buotii, H. halconensis seems to enjoy the rainy season more.  It also bears a night fragrance stronger than H. buotii and the author discovered that the fragrance is the same as that of the classic favourite feminine perfume Tatiana. From cuttings it will take about a year before it flowers.  The nectar of this species is very large and forms into water-like droplets that could easily be mistaken as real water drops.  The author has tasted the sweet nectar (tasting like water with a lot of dissolved sugar in it) and there are absolutely no ill effects unlike the claims and warnings of people who have never tasted or seen the nectars of this species.

3.     Hoya heuschkelliana- the author grew his specimens in pure volcanic cinder and pure pumice but the former seems to grow slower and needs more watering.  After some seven to eight months they begin to flower.  The Lilliputian flowers smell somewhat like an armpit without a deodorant for a day but essence is a very subjective topic.  This plant is constantly in flower with only a very short resting period of two to three weeks before flowering again just a little bit later than Hoya buotii.  Soon enough the plant is covered with many flowers and will surely become a favourite in despite of its small size!

4.     Hoya heuschkelliana var. cajanoae- also grown in the same media just like the species.  The variety grows slower than the species but soon catches up in floriferousness.  It is quite a sight to see the species and the variety growing side by side and flowering side by side too! They have the same odour.

5.     Hoya cumingiana- the plant the author acquired is irradiated and in a medium only a quarter of its pot size.  The planting medium is enriched by autoclaved tissue culture media that have once been affected by bacteria and fungi thus, it is now clean and a very rich fertilizer.  Irradiated H. cumingiana is not as floriferous as the normal ones are.  They seem to prefer blooming during summer or when it doesn’t rain too often.  The flowers do still bear the characteristic musky fragrance (some women do not appreciate this kind of scent) but the colouration is more intense than unirradiated specimens.  Also, the first attempts of the plant in blooming will result in aborting but the succeeding attempts will be successful and the flowers may last for up to a week.  Do not take cuttings from the plant unless it has bloomed already since the plant will be triggered to grow vegetatively rather than concentrate its strength in producing flowers.

6.     Hoya multiflora- planted in ordinary soil, now more than a foot high in a small pot.  This plant seems to enjoy total dryness and a brighter area as the flowers are developing or else they tend to abort.  H. multiflora is also the favourite of aphids and mealy bugs often feasting on its apical growth. It has no fragrance but compensates by giving so much flowers thus the specific name.  Some specimens’ stems even bend due to the heavy and very numerous flowers.

7.     Hoya pubicalyx- one of the most rampant growers and the best known Philippine endemic Hoya internationally, it has strong cinnamon-scented flowers and quite showy too.  However, it produces pedicels only after some two to three years or so and the waiting for the flowers to develop is also painfully slow especially for first time bloomers but they are still worthy waiting for.  This plant grows into a large vine after quite some time and a very large specimen was seen by the author and other CSSP members already draping a massive acacia (Samanea saman) tree in Baras, Rizal Province.

I have discovered that Hoya pubicalyx, a native of The Philippines, produce bigger and more fragrant flowers if the temperature drops more than the usual. The fragrance during unusually cold days are really so attractive even some metres in distance away.

8.     Hoya carnosa- the very first Hoya to be discovered, described, and the type species of the genus.  It is indigenous from southern China to Australia  including the Philippines.  The late Dr. Monina Siar herself found wild populations of this species in some parts of Laguna.  The author planted his specimen in pure soil.  A big specimen of Hoya carnosa can be seen inside the Mandaluyong Botanic Garden/Orchidarium.  It also flowers in the manner of Hoya pubicalyx and bears the same cinnamon fragrance but fainter than the former.  The flowers are also smaller than H. pubicalyx.

9.     Hoya incrassata- too often misidentified and mislabeled, still a mystery among Hoya lovers and causes confusion among some Hoya researchers as it closely resembles Hoya crassicaulis and almost everyone you’ll ask will give you diverse distinguishing hints but are still confusing.  I used to identify the fragrant specimen as H. crassicaulis and the non-fragrant species as H. incrassata.  This is also the distinguishing guide of Mr. Patrick Gozon.  Planted in coconut husk that dries so fast, it must be watered once the medium dries out and twice during hot days.  However, the plant is triggered to flower when it is drier nevertheless prolonged drought will kill the plant. Better water the plant well when flowers have opened and continue until they drop.  Withhold watering again or reduce watering to a minimum when new flower buds are forming.

10. Hoya imperialis- originally found growing among mangrove trees near the Puerto Princesa Underground River (which is now one of the seven natural wonders of the world and thus any wildlife collection is now prohibited without proper permission, documentation, reasons, papers, etc.) was planted in pure pumice by the author.  It enjoys generous watering if grown in this medium.  This is the largest flowering native Hoya species of the Philippines and one of the largest in the world.  The white form is still the undisputed most expensive Hoya species in the world.

11. Hoya ilagii- a plant recently described in the last two years, is still rare in cultivation and even a small stem cutting is very expensive.  One of the main reasons is that this plant has a slow growth and would rather flower than grow vegetatively strong.  The author planted his specimen in pure hydroball/ hydrocorn medium which it seems to enjoy; only that this medium should be carefully watched not to get too dry or too wet.  Hoya ilagii could be grown under bright sunlight but there should be very good ventilation to prevent desiccation.  The blood red flowers of this endemic species is truly spectacular and the author discovered that it has a fragrance reminiscent of chocolates however, fragrance is a very subjective matter and one must personally experience the scent and interpret it himself.

12. Hoya imbricata- perhaps the most bizarre of the Hoya species since the leaves somewhat resemble turtle shells that grow in succession.  The characteristic of this plant might hint to a more succulent lifestyle but the author only succeeded in encouraging vigorous growth by watering it generously. It took a year for the plant to finally grow once the secret was unlocked.  This plant is more suited to be grown in tree trunks since fern slab is now discouraged from being used. This species loves shadier and somewhat wet or moist conditions and never hinder the growing leaves where they want to attach themselves since this plant produces only one or two leaves per month and this is just during the rainy season!

Hoya lasiantha from Indonesia resembles Hoya praetorii so much and is also sought after by collectors; but try growing and flowering them simultaneously or record them in a picture and you'll see there's a lot of difference. Although also delicate, Hoya praetorii grows more robust and is somewhat more forgiving of its caretaker's mistakes.

13. Hoya kerrii- from Thailand and Laos is perhaps the most succulent of the genus Hoya of which I am knowledgeable of. This species captured the attention of the Filipinos during the years 2006 onwards because of their heart-shaped and variegated leaves. Thus, they were christened Valentine Hoya and are sold as single-leaf cuttings. However, most Hoya species are notoriously difficult to grow from single leaf cuttings. 

The problem with Hoya kerrii is that their medium should be very porous and buying a plant with several leaves even if it is a cutting is more advantageous and will assure that the plant will live. However, the succulence of H. kerrii means that it grows painfully slow and likewise its flowering.

I obtained my specimen October of 2008 and not until I transferred it to my Mandaluyong Tengoku no Kokoro-Hagetaka was I able to successfully induce it to flower May of 2013-a 5 year waiting period!

In my own experience, this species needs a very porous medium, enjoys subjected to direct sunlight but provided with sufficient ventilation, and watering every now and then just to avoid desiccation. The spur might develop several years but flower buds will only develop if it meets the requirements it needs to trigger its flower development. The flower takes a month or two before it opens and once it opens around 26-30 flowers will open and they last for around 2 weeks-a very long period for Hoya flowers to stay open!!!

The nectar tastes like water mixed with sugar when I tasted it and another surprising thing is that the nectar is self-sustaining. Meaning if you eat the nectar today, this will be replenished by tomorrow and so on if the nectar is continuously consumed. Another feature this species have is that the flowers will have some 60 or so flowers that would before the spur rests. Some flower petals also do not fold (sorry I forgot the scientific word for it; this just proves that I'm still a human!) until the time they wilt. The flowers also bear a very mild flour scent. (taken from the author's Marvelous Vibrant Plants page in Facebook)

This is the rarer form of Hoya obscura, its alba or white form. This species, endemic to The Philippines, has a mild scent and grows strongly, a perfect beginner's Hoya! At a glance the flowers might resemble that of Hoya lacunosa but the leaves are different.

14. Hoya melliflua- is an endemic Hoya species of the Philippines. It is the first Hoya from the Philippines that was ever mentioned. According to Dale Kloppenburg's magnum opus bible entitled "Philippine Hoya Book", 'The first mention of Philippine hoya that we now have is Father M. Blanco's description of Stapelia melaflua Blanco, now considered Hoya melaflua (Blanco) Merrill in Flora de las Islas Filipinas 1837, with subsequent editions in 1845, 1877-1883.' 

Kloppenburg's book further states that 'It was said to be the only species still found in the vicinity of Manila, Philippines and generally distributed in the region from which Father Blanco secured most of his botanical material.'

This plant in my experience needs to mature first for more than 2 years and then it will bear flowers during the rainy season. Making it one of the few Hoya flowers that enjoy the rains but just like any other flower, it must not be drenched in water. Let the rainwaters touch it lightly instead.

I accidentally planted this specimen of mine in a mixture of vermiculite and ordinary soil and I have never changed that medium ever since. As I have indicated here in some of my previously featured Hoyas, this genus unlike other genera, do appreciate old soil and staying in its pot for years making the lazy grower more successful in making these plants flower.

The Hoya melliflua I have is a single node cutting that was a gift by CSSP President and now (2013) PHS President Tita Dorie S. Bernabe. I transferred the plant to my Mandaluyong Tengoku no Kokoro-Hagetaka a year ago after taking care of it for one and a half year in my Bilibiran, Binangonan Tengoku no Kokoro-Kyujo. 

Today the plant has attached itself to the concrete wall making it more fortified with its roots. The spur will develop from a mature stem that is exposed to the elements. 

I have tasted the nectar of this plant and it tastes like water mixed with sugar but it has the property to make you want to taste it time after time it is legally addictive! The nectar is also notorious in giving stain to clothes that can never be washed clean so be careful when appreciating this ancient Philippine Hoya species up close and personal. (taken from the author's Marvelous Vibrant Plants page in Facebook)

When I bought this Hoya fungii, originating from Hainan Island, China, last September 2014 I never thought it already has a spur and I only discovered it when wilted flowers littered near its area. I was surprised that the spur of this plant rooted!!! Spur is where flowers supposedly develop from but this one is an exemption! I also believe that this species should be merged with Hoya carnosa because there are only minor differences unless DNA analysis would prove otherwise.

      15. Hoya wayetii- is an endemic Philippine Hoya species. I acquired my specimen some time in 2008. It should have flowered by 2009 but this plant of mine almost died due to the El Niño phenomenon that year and because I was a graduating student that I was so much focused on my studies. Another reason is that I was growing it in my Tengoku no Kokoro-Kyujo (Binangonan, Rizal) garden and I was almost permanently staying at our Mandaluyong house due to my studies. I transferred this plant to my Tengoku no Kokoro-Hagetaka (Mandaluyong City) garden in 2011.

Since Hoyas resent movement from one place to another specially if it is about to flower or in active growth, my Hoya wayetii aborted its supposed flowering for more than a year and just yesterday night it awarded me with these lovely blooms! I noticed that it has somewhat an unpleasant smell just like that of Hoya heuschkelliana and H. heuschkelliana var. cajanoae.

Upon acquiring this species, I planted it in mixed soil and crocks in a small plastic pot and I never changed its pot over these years yet it has grown steadily healthy and now it has already flowered. I have it placed in a larger hanging pot in a semi-shaded area and waters it daily. It seems to appreciate abundant watering.

Since Hoyas resent movement from one place to another specially if it is about to flower or in active growth, my Hoya wayetii aborted its supposed flowering for more than a year and just yesterday night it awarded me with these lovely blooms! I noticed that it has somewhat an unpleasant smell just like that of Hoya heuschkelliana and H. heuschkelliana var. cajanoae.

Upon acquiring this species, I planted it in mixed soil and crocks in a small plastic pot and I never changed its pot over these years yet it has grown steadily healthy and now it has already flowered. I have it placed in a larger hanging pot in a semi-shaded area and waters it daily. It seems to appreciate abundant watering. (taken from the author's Marvelous Vibrant Plants page in Facebook)

16. Variegated Hoyas- grows slower and flowers only after four years or so by experience. 

Hoya celata, hailing from The Philippines, was formerly called Hoya "White Dragon" prior to its scientific description. It has a wonderful fragrance. This plant requires watering after two or three days without.

Hoya burtoniae, another Philippine endemic, has small and pretty flowers. It doesn't like getting water-soaked or strong sunlight. I find it best placed under bigger plants and loves to grow in a pendulous manner.

One of the most coveted Hoya species, Hoya praetorii, coming from peninsular Malaysia to the rest of Borneo. It's also one of the most delicate species as I have experienced growing it. Scales love devouring them so be very vigilant!

I found this Hoya in one of our botanical explorations growing in a mangrove tree literally covering the massive trunk with its rampant growth. This resembles Hoya incrassata or Hoya crassicaulis but might be of another species or yet unknown to science.