The Hoya kerrii with its distinctive heart-shaped leaves is a hit in well-stocked garden centers, and not just on Valentine’s Day. With its meter-long tendrils and the pretty flowers from May to October, it serves as a meaningful statement of sympathy. Hobby gardeners also like to treat themselves to this undemanding houseplant, whose flexible habit allows creative decoration ideas to bubble. The sweetheart plant thrives equally on the trellis, in the hanging basket or in the flower pot. Even beginners who still struggle with their green fingers can easily manage care and propagation. The following instructions explain all the important details.
Table of Contents
Characteristics
- Dogbane family (Apocynaceae)
- Genus of wax flowers (Hoya)
- Scientific name: Hoya kerrii
- Native to Southeast Asia
- Colloquially: sweetheart plant, little darling, wax flower
- Growth height on trellis up to 100 cm
- Opposite, heart-shaped, thick fleshy leaves, 4 cm to 12 cm long
- Fragrant, white corollas with a purple center
- Flowering period: May to October
As a tropical plant, Hoya kerrii is not winter hardy. In indoor culture, it will thrive for many years, and during that time it will attain considerable volume if you allow it.
location
If there is still a free spot on the east or west window, the sweetheart plant will feel right at home there. She prefers the brightest possible light conditions. On the other hand, she wants to avoid the blazing midday sun. In the sun-drenched conservatory there should therefore be a shade that closes during the midday hours. Sunbeams in the morning or evening, on the other hand, favor leaf and flower growth. In a place in permanent twilight, the flower fails.
If the chosen location in the room proves to be too shady, a special plant lamp can help. Suitable models are already available for less than 20 euros and are definitely a worthwhile investment before you forego the high ornamental value of a sweetheart plant.
Substrate
In the native regions of Southeast Asia, wax flowers thrive in well-drained soil. This attribute should be primarily applied to the indoor growing medium. Other properties, such as nutrient content and pH value, follow in their importance.
- High-quality potting soil with coconut fibers for good permeability
- Optionally, a proprietary mixture of garden soil, compost and perlite
- Moderately nutritious, with a pH of 6 to 7
A little darling has been proven to be an excellent candidate for hydroponics. In this variant, the root ball is in inorganic material such as expanded clay or seramis. The plant uses itself from a supply of water and nutrients.
pour
In addition to an adequate supply of irrigation water, the highest possible humidity is the decisive factor for successful care.
- Pour Hoya kerrii evenly with lime-free water
- Never use cold water straight from the tap
- The substrate surface dries well between waterings
- Spray the houseplant with rainwater daily during the summer
A humidity level of more than 60 percent is recommended. If spraying is only possible sporadically due to time constraints, there is a clever alternative. The coaster is filled with pebbles and water. The moisture evaporates, creating the desired level of humidity around the sweetheart plant. A bowl filled with water or an indoor fountain also fulfill this task.
Fertilize
The nutrient requirement of the little darling is at an average level. During the growth period from March to September/October, the Hoya kerrii receives liquid fertilizer every 14 days, according to the manufacturer. Less effort is required using fertilizer sticks or fertilizer cones, which act as storage fertilizer for 6 to 8 weeks. If the wax flower has been repotted in fresh, pre-fertilized substrate, the supply of nutrients will not start until the following year.
Clean and cut
If the withered flowers are plucked regularly from the umbels, a second bloom usually forms. The stems and tendrils can take a corrective cut at any time. It should be borne in mind that the bloom visibly reduces with each pruning.
- Shape cutting is not tied to a fixed point in time
- Always start the cut 1-3 mm above a leaf node
- Thin out dry, stunted and diseased shoots immediately
If the sweetheart plant develops so densely in habit that the tendrils take the light from each other, moderate thinning is also recommended. Otherwise there is a risk of bareness from within.
hibernate
A little darling can easily be cultivated indoors all year round. Temperatures between 18 degrees and 25 degrees Celsius provide the plant with sufficient warmth. The vitality of the ornamental plant is significantly boosted if it is allowed to regenerate over the winter. This means that from October to February she is placed in a cooler room with temperatures between 12 degrees and 15 degrees Celsius. The darker the light conditions, the lower the temperature can be. The mercury column should not fall below 10 degrees Celsius. At the same time, the Hoya kerrii only gets enough water to keep it from drying out. Fertilizer is not added during this winter break.
repot
In view of a rather sluggish growth, a repotting is only on the care program every 2 to 3 years.
- Repot Hoya kerrii in February or March
- The new bucket is not significantly larger than the previous one
- Create a drainage at the bottom of the pot over the drain hole
- Fill in fresh substrate, pot and water the wax flower
A small pouring rim prevents water from spilling over. If there are no pebbles in the coaster, the irrigation water collected in it is emptied after 20 minutes.
Repotting in a hanging basket
The sweetheart plant is repotted in a classic hanging basket as well as in a bucket. If you count yourself among the experimental hobby gardeners, choose a hanging basket for a change. These are stylish mesh baskets made of metal or plastic. The beautiful tendrils of a Hoya kerrii find ideal conditions in such a planter to develop magnificently. Regarding the planting, only a little rethinking is required:
- Line the basket with burlap, moss or coconut mats
- Cover the bottom additionally with foil so that the irrigation water does not run out
- Create a drainage over it, fill in the substrate and plant the wax flower
If tendrils are already present, pull them through the meshes of the grid. It may be necessary to have a slot cut in the liner.
multiply
The quite sluggish growth rate causes comparatively high purchase prices for a sweetheart plant. If you want more specimens of this exotic rarity, you can propagate them yourself. With the help of the following instructions, you will have another little darling within 6 to 8 weeks.
- Cut cuttings in February with 3 to 4 pairs of leaves and approx. 10 cm in length
- The interface is just below a leaf node
- Defoliate each cutting except for the top pair of leaves
- Fill 9 cm pots with potting soil or a peat-sand mixture
- Plant a cutting in each and moisten
Ideally, a heatable greenhouse is now available. Alternatively, create a warm, humid microclimate by putting a plastic bag over each pot. Rooting sets in after 6 to 8 weeks on a bright window seat that is not in full sun. During this time, regularly moisten the cuttings and air the cover for a few minutes daily. A fresh shoot signals that the rooting is successful. The plastic bag is now removed, as contact between the leaves and the material often causes rot. If the roots protrude from the opening in the ground, repot the sweetheart plant in normal substrate and care for it like an adult specimen.
Other propagation methods are not available for the hobby gardener or can only be implemented with great effort. Seeds form Hoya kerrii in the local latitudes only extremely rarely. You can hardly find them even in specialist shops.
Disinfect propagation substrate
Whether you buy it ready-made or mix it yourself – you cannot be completely sure that a growing medium is completely free of fungal spores, viruses or insect eggs. A disinfection that works without any chemical agents is therefore recommended. You fill the soil in a fireproof bowl and put a lid on loosely. The vessel goes into the oven, where it stays for about 30 minutes at 150 degrees to 180 degrees top and bottom heat. After it has cooled, use it immediately to propagate your Hoya kerrii.
Disinfection is quicker in the microwave at 800 watts for 10 minutes. Caution – the bowl and substrate are very hot.
Decorative varieties
The intriguing waxflower species Hoya kerrii inspires creative growers to create beautiful strains, of which some popular specimens are featured below:
- Hoya kerrii Craib Albomarginata – A beautiful variety with cream variegated leaves. Without tendrils, it reaches a height of 30 cm to 40 cm.
- Hoya kerrii ‘Yellow Splash’ – Very rare variety with yellowish leaves that turn green towards the edge. The flowers appear in the typical colors white and purple.
- Hoya kerrii ‘Variegata’ – The predominantly green heart leaves are edged with a thin, yellowish stripe.
Within the Hoya family, it is only the Hoya kerrii on which the heart-shaped leaves thrive. While other Hoya species present a similar flower, they only have simple, oblong to oval foliage.
Conclusion
As a tropical houseplant with the status of a rarity, the sweetheart plant is a good choice. Caring for them is not a problem even for inexperienced hobby gardeners. The water and nutrient balance is within normal limits. The location can be chosen flexibly as long as the intense midday sun does not reach there or it is too dark. The Hoya kerrii grows slowly but steadily and develops an extensive biomass. Since it is also pruning compatible, you keep the habitus within the desired framework. A short instruction is enough, and the propagation is very easy. The wax flower is a recommended addition to the living room and conservatory as a houseplant in a pot, in a traffic light or in a hanging basket.
