Wax Flower, Porcelain Flower – Care of the Hoya

We only sell the wax flowers as imported guests. Their care can therefore only be explained and understood after a look at the homeland. The beauties, also known as porcelain flowers, form a genus of their own. Their natural range is very large. However, it is limited exclusively to Asia, Australia and the Pacific islands grouped under the term Oceania.

Occurrence in the rainforest

Within this vast territory, the Hoyas have conquered a wide variety of habitats: They grow in the permanently damp, tropical rain forest of Southeast Asia as well as in the dry forests of northern Australia and northeastern Thailand. They can colonize mountains and there the cloud forests up to an altitude of around 2,500 meters. They also thrive in many different types of forests, along the coast and along river banks.

Creative growth forms

When conquering all these different areas of life, the wax flowers show another special feature: They are not limited to simple growth in the ground, but originally even rarely grow boringly terrestrial. On the earth’s surface, too, they have conquered the most diverse soils, humus and sandy soils, moist and dry soils.

However, many Hoya species have “left the earth”: they have developed epiphytic growth forms. So they grow on or on other plants. These epiphytes or “mountain plants” look for carrier plants such as trees in order to “grow” above the dark forest floor and enjoy a much better supply of sunlight at dizzy heights. However, they do not tap into their host plants like the (half) parasite mistletoe does, but are still dependent on a continuous supply of nutrients and water.

Since this supply can sometimes be difficult high up in a tree, epiphytes have developed a wide variety of ideas on how to “get fed” even without contact with the ground. There is e.g. B. Hoyas, which live in close symbiosis with ants in the rainforest. Other porcelain flowers stay on the ground, but still do not grow in soil, but lithophytically, i.e. on or in stones. With their roots, these growth forms cling to the rock or even penetrate it. They get their sustenance from the air, from dust and rainwater, from moss substrates or “from themselves”, from dead plant tissue.

So the Hoyas have proven that they can cope with a wide variety of living conditions, but always in a tropical climate and not in the German cold. However, the natural forms at least give us a lot of clues as to how we can cultivate a wax flower.

Different attitude

Because you can think of very different planters in different places in your home for a wax flower:

• You can hang a hoya in a hanging basket, at any height, as it is used as an epiphyte.
• Wax flowers can also be kept in the ground. Most Hoyas germinate as young plants in the forest floor and only then “climb into the trees”.
• You can use plastic pots to pot the Hoya, but clay pots and other materials are also suitable.
• It is important that you sterilize the pots before potting the hoyas and remove any remaining roots from the previous plant.
• Since the “foreign guests” could react sensitively to all sorts of microorganisms etc. from our environment, special cleanliness is generally announced.
• This cleanliness should be extended to every item that comes into contact with the plants, from the soil mixing container to the last tool.

Equally broad is the field in relation to the substrate in which the hoya is held

• Actually, almost anything is suitable that can hold water and nutrients and does not overwhelm the Hoya with unknown substances.
• First of all, this means that commercial potting soil is not such a good environment for a Hoya that has been enriched with artificial fertilizers etc.
• The same applies, of course, to all sorts of special mixtures from the trade (the chemical composition of which is usually indistinguishable from potting soil).
• Even our garden soil would confront a Hoya with too much unknown. A loose mixture of sand with mature compost should be well tolerated.
• A wax flower can also be kept in many other substrates, e.g. in perlite. B. in coconut humus, in clay or tree bark.
• A hydroponic environment is also a suitable environment for Hoyas, or the fleece grow bags that are on the rise.

In addition to these basic options, which are actually available for all Hoyas, it also depends on the special needs of your Hoya. There is e.g. B. Porcelain flowers that live on limestone, and they would like a little lime in the substrate. So when you buy it, ask exactly how you want your special wax flower to be held and refrain from buying an expensive Hoya if these questions cannot be answered.

Culture guidance and care of the Hoyas

If the basic housing conditions are regulated, wax flowers that are hung high and kept in tubs on the ground are treated in much the same way:

All home areas of the wax flowers are much closer to the equator than Germany, so the Hoyas are used to significantly higher light intensities and really need all the light that is available to us. The brightest and sunniest location in your home is just right for the wax flowers, or it is already too dark, you will notice this at the latest when your wax flowers in “stories” get leaves and do not bloom. The Hoya can then remain in a favorable location, the porcelain flower is one of the few plants that do not benefit from being outdoors in summer. It is even more likely that she will react harshly to a change of location, and with night temperatures of around 10 degrees it gets too cold for her, so it is best to just leave her alone in the apartment.

Otherwise, wax flowers like the indoor temperatures we are used to and even watering during their main growing season. But no foot baths please, so the next water is only given when the top layer of soil in the pot feels dry.

The cut of the wax flowers

Climbing plants like the Hoya carnosa can definitely “grow over your head”, in the truest sense of the word, and maybe also the coarse meshes of the curtains. When that happens, you can trim a Hoya with ease, as far as needed.

You should always end the pruning above a leaf axis, from which the plant will sprout again. In some Hoya species, the flower stalks also develop from these new shoots, others flower on the old stalk, so if you can leave out shoots with flower stalks when pruning, these should be retained.

The best way to do this is to grab a shoot that has become too long at the top of the plant, expose it down to the depth of the plant and then cut it away. You do this shoot by shoot, so you never have to cut uncritically anywhere in the middle of the plant, which could cut off a lot of shoots that are supposed to be preserved.

You can also cut away the withered parts of the plant after flowering. With some Hoya varieties, you may only remove the flowers themselves and the small stalks of the umbel; the stalks remain on the plant because they form the new flowers. Other Hoyas flower on the new shoots, here the old flowers can be completely removed.

multiply hoyas

If such pruning measures become necessary, the time just before new growth is optimal. Then you can immediately grow new Hoyas from the removed shoots: you simply place the removed shoots in a glass of water, where they will take root in not too long. When the first few leaves are developed, the young hoyas are transferred to the desired culture environment.

nutritional needs

In their natural environment, hoyas (high up in the tree) are not always spoiled with an abundant supply of nutrients. But at least they live outdoors, an ant will drop by every now and then and leave some manure, the air will provide some “bird gifts”, old leaves and a bit of bark, and the rainwater will bring the Hoyas nitrogen free to their homes.

In your living room you have to replace all these natural phenomena by feeding your plants with water and fertilizer. One difficulty with this is that the fertilizer, which is usually sold as a concentrate, can be overdosed very quickly. If in doubt, it is better to apply a slightly too weak solution than too much fertilizer, most plants do not cope very well with overdoses.

Then it depends on the composition of the fertilizer, for the wax flower the following mixture of the three main nutrients is recommended: 2 parts nitrogen, 1.5 parts phosphorus and 2 parts potassium, so something like “NPK 14/10/14” should be printed on the package. or “14/11/12” may be printed.

You can see whether your Hoya sees it differently. You will notice a lack of nitrogen on the leaves. The older leaves discolour, curl up, dry up and fall off. The fresh leaves also take care of themselves. Too little phosphorus is also evident on the leaves, but first on their edges and tips, which begin to turn brown in the older leaves. Also, they will curl up and eventually turn all sorts of colors, brown or yellow, greenish-bluish or reddish, and growth will also slow down. Rolled-up leaf tips with brownish leaf edges indicate a potassium deficiency, especially if the remaining edges of the leaves also curl up later and the leaves turn yellow below. Hoyas that are cultivated in soil are said to tolerate or need significantly more potassium.

Of course, such a written description always leaves a lot of room for imaginative interpretations in every direction. Therefore, if you, as a Hoya novice, have the opportunity to discuss fertilizing a mismanaged waxflower with an experienced Hoya professional, you should definitely take it.

Repot wax flowers

Repotting the Hoyas is not a problem. You can transplant the wax flowers into larger plant pots by eye when the root mass has penetrated the pot so extensively that it can already be seen on the surface of the earth. This can happen every spring with vigorous Hoyas. Until it sits in the largest pot that you would like to see in your apartment.

However, you should not overdo it with the repotting. If it happens for no reason, the Hoya usually doesn’t like the disturbance any more than a change of location. We don’t keep most of the wax flowers so well that they have to be repotted all the time. A smaller pot is also more likely to encourage the plant to put in a lot of effort to develop buds.

There are many varieties of porcelain flowers

The wax flowers form their own genus within the milkweed family, the number of members of which is quite controversial in science. Some botanists assume around 100 Hoya species, others want to have counted 400. Quite a few of these species are cultivated as ornamental plants, and many different varieties of these have been bred.

A dealer who specializes in Hoya will therefore present you with a highly exciting selection of wax flowers. Varieties with white and with yellow and with light pink flowers appearing in compact round balls or in semi-circles or in loose umbels, closely packed or widely spaced. It is not uncommon for you to be able to choose from over 80 different Hoya varieties.

Hibernate Hoya

The wax flowers, which are hungry for warmth, do not know frost and in our climate, of course, have to overwinter in heated rooms. Most wax flowers do well to rest in winter. However, the exact conditions for this hibernation can vary slightly depending on the variety:

• The frequently sold Hoya carnosa likes e.g. B. in winter, temperatures between 12 and 15 degrees when kept so dry that they just don’t dry out completely.
• She even needs this hibernation to start flowering here.
• Also better-known species Hoya bella and Hoya australis enjoy a winter break, with limited watering, but temperatures around 18 degrees.

Conclusion
The wax flowers are really extremely interesting tropical flowering plants, whose porcelain-like flowers delight with their fragrance. Don’t lose patience if a Hoya doesn’t flower immediately, it can take years. But the wax flower can also become decades old.