The wax flower - also known as the porcelain flower - is a popular houseplant because of its beautiful flowers and decorative leaves. We will introduce you to some types of porcelain flowers and explain what you should consider when planting and caring for wax flowers.
The wax flower is an evergreen houseplant. It produces small, star-shaped flowers that have a characteristic waxy sheen and come in a variety of colors depending on the species.
Wax flower: flower, properties and origin
Waxflowers (Hoya), also known as porcelain flowers, form a genus in the subfamily of milkweed (Asclepiadoideae), which belongs to the dogbane family (Apocynaceae). The natural range of porcelain flowers extends from Asia to Australia to Oceania. The evergreen houseplants grow partly in the ground (terrestrial), partly epiphytic, that is, as "mounters" on other plants. However, wax flowers are not parasites; they take root, for example, in old, already decaying bark. The plants form aerial roots and have a very low nutrient requirement, but good opportunities to store water. In addition, they usually prefer high humidity because otherwise they would dry out quickly.
Wax flowers are herbaceous plants that only slightly woody and are often grown on arches due to their flexibility. They have a vigorous growth and their shoots can be several meters long. Some of them grow like lianas, other types grow more as semi-shrubs. Due to the overhanging growth, they are well suited for planting in hanging baskets. Other species show a climbing habit with adventitious roots that form on the shoot axis.
The flowers of the wax flower appear between spring and autumn. Numerous individual flowers, around 1.5 cm in size, form large pseudo umbels. The individual flowers are star-shaped and, depending on the type and variety, soft pink, white, purple or alsocolored pale yellow. The perianth has a double structure. Outside there are five fused petals, inside there is another row of five fused, slightly smaller petals. In the very center are the sexual organs of the flowers. The second row of petals is often colored differently than the outer one. In most species, the flowers exude a sweet scent and secrete nectar. They also have a wax-like sheen. With their characteristic flower structure, Hoyas are among the pinch trap flowers that have an exceptional pollination mechanism. The flowers have so-called clamping bodies, with which the wax flower flowers pinch insects visiting the flowers for a certain time. The pollinia, which are sticky packets of pollen, are located on the terminal bodies. When the insects free themselves from the "grip" of the flowers, they often tear the sticky packets of pollen out of the clamping body and carry them on to the next flower, which is pollinated in this way.
The approximately 5 to 8 cm long leaves are slightly ovate and taper to a point. They are dark green in color, succulent, i.e. thickened to store water, and usually have a waxy, shiny surface.
The most beautiful types of porcelain flowers
The genus Hoya includes over 300 species of porcelain flowers. Here is a small overview of the most popular types:
Hoya carnosa is a very easy-care species and is probably one of the most common Hoya- Species. It shows a fast and climbing growth. Their leaves are usually dark green and shiny. However, there are also varieties with white variegated and twisted or wavy leaves. The flower of this wax flower is made up of porcelain white or pink and dark red petals.
Hoya bella is a small, compact wax flower with a strongly branching habit. Its leaves are grey-green in color and have a matt sheen. The pseudo umbels are made up of white, star-shaped individual flowers whose centers are bright red.
Hoya multiflora differs among other things in the flower shape from the previously mentioned wax flowers. The individual blossoms are strongly curved to the sides and thus look like arrowheads. They are also slightly larger than the porcelain flowers above. They have a ring of white and a ring of yellow petals.The dark green leaves of H. multiflora are thin, elliptical in shape and slightly wavy.
Also Hoya imperialis stands out because of the slightly wavy leaves. However, the most striking feature of this species is the size of the slightly forward-curved flowers. The pink to violet colored individual flowers are about 5 cm in size and have a waxy shine. The central petals are white.
The species Hoya kerrii, also called sweetheart plant, is also particularly popular. It stands out because of the heart-shaped shape of its leaves. The flowers are white in most of the associated varieties.
Plant wax flower
If you have found the right wax flower for you and want to plant it, you need to look for a suitable location, choose a suitable planter and a suitable substrate.
Correct location and soil for the porcelain flower
First of all, it should be noted that each species has its individual requirements and only a few similarities can be mentioned here.
So that your wax flower feels good and can develop well, you should put it in a sheltered, bright and warm place in your home. A window sill, for example, is good, but porcelain flowers do not tolerate direct sunlight, which must be taken into account when choosing a location. The latter can be attributed to the fact that in their natural habitat wax flowers are found under the leaves of the trees on which they grow. Some Hoyas even prefer to grow in shady areas. Drafts should also be avoided. In addition, wax flowers love a slightly higher humidity. It is therefore advisable to spray the plants with a little low-lime water from time to time.
The ideal room temperature is between 18 and 25 °C, depending on the species. During the winter months, the wax flower is in a kind of hibernation and should be placed in a cooler place with temperatures between 10 and 15 °C during this time. This promotes flowering.
When choosing potting soil, good root aeration and avoiding waterlogging are the most important factors for the he althy development of wax flowers. As epiphytes, most species of Hoyas are accustomed to their roots being well aerated. Unfortunately, you cannot buy a special "Hoya soil" - so your own mixture is the only option that meets the needs of the Hoyafulfill. A peat-free potting soil such as our Plantura organic universal soil is very suitable as a basic substrate. To eliminate any sagging and lower the nutrient content, it should be mixed with 30% expanded clay and 30% pine bark or orchid soil. This makes the substrate more structurally stable, less nutrient-poor and the pH value is lowered - perfect conditions for he althy Hoya roots.
How to plant wax flowers
Be sure to choose a pot with a drainage hole, because wax flowers are sensitive to waterlogging. If the roots are permanently wet, soil-borne pathogens quickly find a good basis for life and manifest themselves in the form of root rot. The wax flower is removed from its plant container and placed in the middle of the substrate in the planter. Now it is filled with substrate and pressed.
Summary: Plant Wax Flower
- Location: Sheltered, bright and warm place without direct sunlight
- Room temperature: 18 - 25 °C
- Substrate: Mixture of potting soil - like the Plantura organic universal soil - expanded clay and pine bark/orchid soil
- Choose pot with drainage hole
Porcelain Flower: Care
In general, wax flowers are quite frugal indoor plants. Apart from regular watering, occasional fertilizer application and repotting when the entire pot is rooted, no further care is usually necessary.
Watering the porcelain flower
Porcelain flowers should be watered regularly, but not too much, during the growing season from March to October. After watering, wait until the substrate has dried and only then add water again. In winter, wax flowers need to be watered less often and the amount of water should also be reduced. The latter is particularly important when the substrate is not permeable enough. This is the case, for example, if normal potting soil was used.
Fertilize wax flower
The same applies to fertilizing the wax flower as to watering it. Fertilizer should be applied every three to four weeks during the growing season. A green plant liquid fertilizer such as our Plantura organic indoor and green plant fertilizer is ideal for this. It supplies your green plants with all the important nutrients and is applied with the irrigation water. The dosage is 15 to 25 ml per 5 liters of irrigation water. You should not fertilize the porcelain flower in winter.
Repot porcelain flower
Porcelain flowers not only grow above ground, their roots are also spreading underground. Therefore, you should repot your porcelain flower as soon as the pot gets too small. The new pot should only be a few inches larger than the old one. The right time for repotting is between February and March. Older wax flowers in particular suffer from transplanting, which is reflected in a reduced formation of new flower buds. So it is better not to do this too often. When repotting, pruning is also a good idea - spring is also ideal for this.
Cutting wax flower
Garxflowers should only be cut when they become too sprawling. As a rule, new buds keep forming on the old flowering shoots, which is why it would be a shame to remove them early. If you still want to cut your porcelain flower because it is getting too big or not growing in the shape you want, you should always position the scissors or the knife above a leaf axil (node) so that the Hoyacan sprout again at this point.
Porcelain flower not blooming: what to do?
Porcelain flowers react to various situations and conditions with reduced flowering. Sometimes it even happens that wax flowers do not flower at all. In this case, the cause can be, among other things, an excessive supply of nutrients. Therefore, wax flowers should not be fertilized too much. Another reason for a lack of flowering can be overwintering at too high temperatures. For this reason it is important that the Hoya is placed in a cool place in good time. It is also advisable, if possible, not to cut back the porcelain flower, as it also forms new flower buds on old flowering shoots. Last but not least, the wax flower should not be moved or rotated once the correct location has been found. Porcelain flowers usually set their blossoms on the side facing the light. If you rotate the plant before the flowers open, the buds may fall off.
Propagating porcelain flowers by offshoots: layering and cuttings
Porcelain flowers can be propagated vegetatively in two ways, namely by offshoots and by cuttings. The propagation of cuttings works as follows: In the spring, approximately 10 cm long, only slightly woody shoot tips and shoot parts are cut off the wax flower. SubsequentlyThese are placed in pots filled with moist, loose and nutrient-poor potting soil and placed in a bright place without direct sunlight, for example on a windowsill. For example, our Plantura organic herb and seed soil is suitable as a cutting substrate. To make it even looser, you should add some sand, perlite or crushed expanded clay. At temperatures between 20 and 25 °C and regular watering, the cuttings will root within two to three months.
As an alternative to propagation by cuttings, the porcelain flower can also be propagated very well using layering. For this you need a pot filled with the above-mentioned substrate mixture, into which you lower a shoot of the mother plant. This means you carefully bend down a tendril and place it on the substrate. At the point where the shoot is in contact with the ground, the leaves are removed and permanent ground contact is established by fastening the tendril with a peg, for example. The shoot tip is then shortened somewhat. As with propagation from cuttings, it takes time for roots to form. When this has happened and the shoot sprouts again, the propagation has been successful and the cloned plant can be cut off from the mother plant.
In addition to the vegetative propagation methods mentioned, generative propagation via seeds is also possible.
Pollination is only carried out by specialized insects - but this can be helped with a brush, which you can use to go from flower to flower and from plant to plant. Seed pods form, which eventually burst open. The pods should first be covered with a fine net so that the seeds are not thrown so far away.
The seeds are germinable for a maximum of one month, which is why you shouldn't wait too long before sowing. Seeds are spread on a Hoya substrate mix but not covered with substrate as they are light germinators. The soil should always be kept moist. It is also advisable to cover the pots with a small greenhouse or with foil so that the humidity is increased and there is no draft. Place the growing pots in a warm place, the temperature should be around 20 °C. Seeds usually germinate within a few days and quickly grow into small Hoya plantsapproach. However, the rate of growth and development is highly dependent on the species.
Winter wax flower
Porcelain flowers don't like the cold. It is therefore best to place your wax flower in a bright spot in the apartment or in the conservatory after flowering. The temperature is ideally between 10 and 15 or a maximum of 20 °C. It should not be warmer, otherwise the plant will form long, flowerless winter shoots. Furthermore, the houseplant should not be exposed to strong temperature fluctuations or draughts. During the winter months, the wax flower only needs to be watered rarely and with small amounts of water. Fertilization is not necessary during this period.
Is the porcelain flower poisonous?
Porcelain flowers are poisonous. Some Hoya species are considered to be highly poisonous in exceptional cases. Wax flowers contain cardioactive glycosides that are potentially fatal. Because of the unpleasant taste, however, not a single case of poisoning has been reported so far. Small amounts induce vomiting. So our body protects us from a lethal dose.
In addition, Hoya carnosa can be an allergy trigger. An allergy occurs earlier if people who are susceptible to it are in regular contact with the plants (e.g. when cutting, watering, repotting). Symptoms include a runny nose, red eyes, cough and asthma. In these cases, the allergen enters the airways via the air. Other symptoms such as skin reddening and eczema arise as a reaction to skin contact. If the symptoms mentioned occur, one should consult a doctor and mention that one has a wax flower in the house. It could be the trigger, which can be checked with a blood test. If this is the case, it is advisable to remove the plant from the house.
If you are interested in other, possibly low-maintenance, plants for your home, you can read more about our special article on low-maintenance house plants.