Cineraria is a hybrid plant, a cross between Pericallis cruenta and P. lanata, species that are native to the Azores and Canary Islands. Cineraria is a tender perennial, hardy in USDA cold hardiness zones 9 to 11, but it is usually grown as an annual or short-lived seasonal houseplant.
Known for a wide range of colors and long-lasting blooms, Cineraria comes in vibrant shades of pink, red, purple, blue and bi-colors. It is a mound-forming plant with large leaves that becomes covered with blossoms during its blooming season. Cineraria prefers cool weather, so as a garden plant it is usually grown for spring blossoms and then removed from the garden in favor of summer-blooming annuals after the bloom period is over. Many gardeners prefer to use them for container culture rather than as in-ground bedding plants.
As outdoor plants, cineraria plants are usually planted from nursery starts in the spring, which have been commercially grown to provide cool-season spring blooming. But these plants bloom about four months after seed germination, so it’s possible to dictate the bloom period by carefully selecting the time when you sow seeds. Sowing in late summer, for example, can give indoor flowering plants for Christmas.
The flamboyant colors of cineraria, as well their versatile daisy shape, have made them increasingly popular in the United States in recent years as a decorative, cool weather annual. If you happen to live in a very warm zone (USDA cold hardiness zones 9 to 11) you can try growing them as perennials. As an annual, they hold their color for a decent period of time, so make sure they stay evenly moist and deadhead them continually to encourage new buds, and you’ll have weeks of glorious colorful blooms from spring through summer.
Cineraria will do best in filtered sunlight or partial shade conditions and it resents full sunlight. If grown as a short-lived indoor plant, however, it likes bright but filtered sunlight.
Cineraria like a rich, moist, slightly acidic soil that has good drainage. Amendments such as peat moss and coffee grounds can help create good soil conditions. When grown indoors, a standard potting mix works well because it contains a high percentage of peat which ensures an acidic soil pH.
Cineraria needs constant moisture but it still needs to breathe. Water well and frequently at the base of the plant, checking the soil to make sure it feels moist but not soggy. Steady watering in hot weather is a must. But at the same time, it doesn’t like constantly soggy soil, which can encourage root and crown rot diseases. Thus, it’s critical that frequent watering is paired with well-draining soil.
Temperature & Humidity
Cineraria is temperamental about temperature. The preferred temperature is between 50 and 65 F. If temperatures dip below 35 degrees at night, the plants will die, and if the temperatures go above 80 degrees, they’ll stop blooming. In the heat of summer, make sure cineraria plants are shaded; it might be necessary to bring potted plants indoors during very hot days.
When grown indoors, cineraria plants like a cool environment; they will bloom longer with daytime temperatures of about 65 F and nighttime temps of 50-55 degrees.
These plants thrive in an environment that is humid yet not quite tropical. Even if your location is not consistently humid, you can approximate the environmental needs of this plant by keeping the soil around it consistently moist. However, avoid making the ground too soggy as this can cause root rot. The best way to provide this humidity for both indoor and outdoor plants is to create a pebble tray. Spread a layer of pebbles or pea gravel on a low dish or tray and place it beneath the container. Keep filled with water up to a 1/2 inch in depth (that might mean refreshing it daily if your house has dry air). As that water evaporates it will create an evenly humid atmosphere around the plant. Misting is not recommended as it can overwhelm the flower petals.
Feed cineraria plants with a half-strength balanced fertilizer every two weeks beginning at the point where flower buds appear. These plants have a steady appetite, but don’t want to be gorged with fertilizer.
Types of Cineraria
Cineraria is usually offered in various named color mixes. Some popular ones include the ‘Senetti’ mix, which includes blue, light blue, magenta, pink, and bicolors; ‘Cruenta Amigo’ mix, including blue, red, purple, magenta, and white flowers, often with white eyes; ‘Satellite Mix’, featuring ground-hugging eight-inch plants; and the ‘Early Perfection’ series, with compact eight- to ten-inch plants ideal for small pots.
Deadheading spent flowers will keep the plants looking tidy and extend the bloom season by prompting the plant to produce additional flower buds. After flowering is complete, these plants are usually pulled out and replaced with warm season, summer-flowering annuals.
Potting and Repotting
When grown in containers, cineraria does well in an ordinary commercial potting mix with a high peat content. For best bloom, they prefer to be somewhat root-bound, so small containers with good drainage are usually sufficient.
These are not easy plants to grow indoors as houseplants because they require careful control of temperatures (cool) and humidity (high). Give indoor potted plants more light than is required for outdoor plants.
Once they flower, cineraria is reluctant to bloom again, so the plants are often removed from the garden once flowering is complete.
If you live in a climate where cineraria can be grown as a garden perennial, you might want to leave the plants in place so that they will self-seed and create new volunteer plants.
Common Pests & Diseases
Cineraria is subject to quite a number of plant pests and diseases. Indoor plants are often more susceptible than outdoor garden plants.
Aphids, thrips, spider mites, white fly and leaf miners can all feast on cineraria. The best treatment is a spray with a horticultural oil such as neem oil.
Disease issues include powdery mildew, gray mold, fungal rot of the crown or roots, and various plant viruses. Keeping soil moisture levels and humidity levels correct will prevent many disease problems, but badly affected plants might need to be removed.
How to Get Cineraria to Bloom
Failure to bloom can usually be traced to a lack of water or nutrients. Cineraria is a relatively demanding plant that needs a half-strength feeding every two weeks. Frequent light feeding is the key to good flowering. These plants also require soil that is consistently moist but not soggy.
Common Problems With Cineraria
The trickiest part of growing cineraria is getting the moisture levels right. Too much water induces root or crown rot, while too little water will prevent the profuse blooming that these plants are famous for. They are also quite sensitive to temperature, preferring coolish conditions and often succumbing when conditions are too warm. It’s best not to grow cineraria at all if you live in a very hot climate, and excessively dry or rainy conditions are also problematic.
How was cineraria developed?
These, cheery, colorful daisy-like flowers are in the Asteraceae (aster) family, which also includes sunflowers, daisies, strawflowers and ageratum. The parent species (Pericallis cruenta and P. lanata) were first discovered by horticulturists from the British Royal Gardens in 1777, growing in the Azores and Canary Islands on cool ocean cliffs overlooking the Atlantic. The varieties now popular in the trade are derived from the hybrid cross of these two species.
How can I use this plant in the landscape?
Cineraria is most often used as an annual, either for garden beds or more often as a container plant for patios, decks, or window boxes, or as a short-lived indoor flowering plant. There is nothing subtle about cineraria, so they are popular whenever you want to make a bold color statement. The cobalt blue shades are especially popular in summer to create red, white, and blue arrangements for Independence Day.
How long does cineraria live?
Even when it can be grown as a perennial in warm climates, cineraria does not readily rebloom after flowering, so in most areas, this short-lived plant is simply discarded after the flowering is complete.
How do I force cineraria into winter blooming as a houseplant?
Cineraria is a seasonal bloomer that generally flowers 16 – 18 weeks after seeds germinate and sprout. Thus, it’s easy enough to dictate the bloom period by choosing the proper time to plant the seeds. For Christmas bloom, for example, you should plant seeds in late August to early September. Remember, though, that it’s tricky to provide the proper cool and humid conditions when growing this plant indoors. This is why many people seeking winter-blooming plants simply buy them in season from a houseplant supplier.
Informationh courtesy of TheSpruce.com