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 (deadheading). 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.