Crossandra plants can be thought of as slightly easier cousins of the hibiscus, though they aren’t related. Also known as firecracker flower, crossandra is native to Sri Lanka and southern India. It features narrow, oblong leaves and showy peach or coral flowers. It’s grown as a bedding plant in tropical and subtropical areas and as an annual in northern areas. It also can be grown indoors. Crossandra is best planted in the spring and is a moderate to fast grower. If you meet its requirements for moisture and light, your plant should bloom in about seven months. Plus, when growing crossandra plants outdoors, they’re known to attract butterflies.
Crossandra is among the few plants that provide months of lovely blooms in partial shade. Thus, it is especially valuable when paired with other shade-tolerant plants for color, including impatiens, coleus and shrimp plants. Indoors, crossandra is tolerant of low light and will provide long-lasting flowers from late spring to autumn.
You can enhance the number of blooms you get from your crossandra plant by removing old and dying flowers. The key for successful growth overall is to meet your plant’s moderate to high moisture and humidity requirements and to protect it from cold temperatures.
These plants thrive best in bright, indirect sunlight. During the summertime, do not expose them to direct sunlight. But in the winter, provide as much light as possible. Indoors, your plant can do well with bright artificial light if you don’t have a sunny window.
A rich, peat-based, fast-draining potting soil is ideal for crossandra. When grown outdoors in the ground, it needs to be in a spot with excellent drainage, and it will enjoy having compost mixed into its soil for the added nutrients.
During the growing season, water frequently and never allow the soil to dry out. Crossandra plants are very susceptible to drought and like a slightly moist—but not soggy—soil at all times. Reduce the amount you water in the winter, even if you’re growing your crossandra indoors in a pot.
Temperature and Humidity
Crossandra is very heat-tolerant and cold-sensitive, as befitting a plant that comes from the tropics. If the temperature goes below 55 degrees Fahrenheit, the plant can experience damage to its leaves or the top growth. Crossandra also likes high humidity. In arid climates, it might be necessary to mist your crossandra weekly during the growing season to provide sufficient humidity. You can raise the humidity for indoor plants by placing them on a tray of pebbles that is filled with water, as long as the water doesn’t touch the bottom of the pot.
Feed your crossandra with a weak liquid fertilizer every two weeks throughout the growing season. Cut fertilizer back to once a month in the winter.
Potting and Repotting
Although they are perennial shrubs in their native habitat, it’s not uncommon for gardeners to treat crossandra plants as annuals, only keeping them until their bloom is over and their leaves begin to drop and then discarding the plants. If you do overwinter your plant, repot it in the spring into a slightly bigger container with fresh soil. Provide plenty of indirect, bright light for the transplant to help it adjust.
Common Pests & Diseases
Crossandra plants typically don’t have pest or disease problems. But they can be vulnerable to mealybugs, mites and aphids. Signs of infestation include tiny webs on plants, clumps of white powdery residue or visible insects on the plant. Treat infestations as soon as possible to prevent them from spreading to the rest of your collection. As always, start with the least toxic treatment option first, only progressing to harsher chemicals if your initial efforts fail.
Information courtesy of TheSpruce.com