Sinningia, also known as gloxinia or bright eyes, is a popular houseplant with velvety green leaves and large bell-shaped flowers. The dazzling blooms come in a range of brilliant colors including red, purple, pink, and white, as well as many color combinations. Cultivation is relatively easy, but gloxinia does have particular light requirements and the plants go dormant for several months of the year. Keep reading to learn how to grow, care for, and propagate sinningia plants.
What is sinningia?
Sinningia plants, like African violets, are gesneriads. Most of the sinningia plants at garden centres are hybrids of Sinningia speciosa, also known as florist’s gloxinia. It’s a seasonal plant that grows from a tuber and has an active growing and flowering period followed by a dormant period. The large scalloped leaves grow in a low rosette with the flowers emerging in the center of the foliage. When gloxinia begins to flower, the bloom period can last for several months. This sizeable flowers can be white, pink, red, purple, or two-toned. They may also have smooth or frilly petal edges, and single or doubled flowers. Most sinningia flowers grow about three inches across and each plant can produce several dozen blooms per flowering cycle.
How to grow gloxinia
There are three ways to grow gloxinia plants: by purchasing a pre-grown plant, by planting tubers, or by sowings seeds. Below you’ll learn more about each of these three techniques.
1) Buy a potted plant
Sinningia plants are sold in spring at garden centres and year-round at florists. They’re also available through online plant vendors. Starting with a plant gives you a head start on the flowering season with most plants already budded up or in full bloom when you buy them.
2) How to plant a sinningia tuber
The flattened tubers are available in spring from garden centres or florists and often have sprouts when you buy them. Once you get them home, pot up the tubers in a container that offers two inches of growing space on either side of the tuber. A 6 inch diameter pot is an ideal size. Fill the container with pre-moistened African violet potting mix. Nestle the tuber into the growing medium with the ‘hollow’ side up. Cover with a scant quarter inch of potting mix. Don’t bury the tuber deeply. Water the soil well and place the pot in a spot with bright, indirect light. The large blooms should appear about 4 months after planting the tubers.
3) How to sow gloxinia from seeds
Seeds can be collected from the seed pods that mature after the flowers fade or you can order gloxinia seeds from a seed catalog. To plant seeds, fill a container or plant tray with pre-moistened African violet potting mix. Sprinkle the tiny seeds on the soil surface and then spray the top of the growing medium with room temperature water to ensure good soil-seed contact. Cover the container or tray with a humidity dome or a sheet of clear plastic wrap. Move the container to a warm site with bright, indirect light. You can also place the seed trays beneath a grow light. Germination typically takes 2 to 3 weeks. Once the seedlings are about an inch tall, carefully prick them out of the container or tray and move them into individual pots. It takes about six months for sinningia plants to bloom when started from seeds.
The best light for sinningia
It’s important to get the light right when growing gloxinia. Look for a location that provides bright indirect light. Don’t place a sinningia in a site with full sun as this will scotch or burn the leaves. A few hours of sun is ok, particularly if growing gloxinia in winter. Avoid low light conditions which can reduce flowering and prompt issues like basal rot. Another option is to grow sinningia beneath grow lights. You can use florescent or LED grow lights, leaving them on for 14 to 15 hours each day.
How often to water sinningia
Ideally, the growing medium of sinningia should be kept lightly, but consistently moist. Use pots with good drainage. Don’t allow the plants to dry out, but also don’t overwater them. Too much water can lead to basal rot. Before you grab your watering can, use your finger to access soil moisture. If it’s dry a half inch down, water the plant. When watering, irrigate the growing medium, not the plant. Try to avoid splashing water on the leaves which can result in brown spots on the foliage.
How to care for sinningia
Sinningia is a relatively low care houseplant. Fertilize sinningia plants monthly with a liquid organic flower fertilizer mixed at half strength. You can also use flowering plant fertilizer spikes that are pushed into the growing medium. Another task is to clip out flowers as they fade. This can encourage new flower production and extend the flowering period.
Propagating gloxinia is an easy way to get more plants. One of the most reliable methods of propagation is to take leaf cuttings. Using clean garden snips, cut off a leaf that is at least 2 inches in diameter where it attaches to the stem. Dip the end of the leaf stem into rooting hormone and insert it into a container filled with moist potting mix. Cover with a humidity dome, sheet of plastic wrap, or place the pot into a clear plastic bag. Within a month or two, a tiny new plant will form at the base of the leaf. If you have more than one leaf in the container, remove them as they grow, and place them in their own pot.
Pests and diseases that affect gloxinia
One of the most common issues that affects gloxinia is basal rot, which is caused by overwatering. Keeping the plants in low light can also prompt rot because the soil is slow to dry out. Aim to give the plants bright, indirect light and check the soil often to make sure it’s lightly moist, not wet. Gloxinia can also fall prey to insects like aphids, thrips, and cyclamen mites. Keep an eye on the plants and if you notice stunted growth or stippling on the leaves, take a closer look. Insecticidal soap can be used to control pests.
What to do with a gloxinia plant after it flowers
Once a gloxinia plant has flowered, the leaves die back and it goes dormant. Don’t be alarmed as this is part of the normal growing cycle of sinningia. Some gardeners treat the plants as annuals and compost them once the flowering period has ended. Or, you can keep the plant and let it go dormant. Once the flowers fade, reduce watering. As the leaves brown and wither, stop watering and move it to a cool, dark spot with a temperature in the 50 to 60 F (10 to 15 C) range. Dormancy can last for up to 4 months. When you see new shoots emerging from the tuber, repot it in fresh potting mix and move it back to a brighter location. Start watering and fertilizing regularly.
For more information on growing indoor plants, be sure to check out these in-depth articles:
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- An in-depth guide to caring for string of dolphins
Are you interested in growing a Sinningia plant?