Mini rose plants are a common sight in nurseries and grocery stores for good reason, as these tiny rose cultivars are a charming, colorful addition to a garden or interior. Though the plants are often grown for a season and tossed away, mini roses can have a long lifespan with proper watering and care.
Miniature roses love sunlight, and those grown indoors need as much light as possible to thrive. Place the plant in a bright, sunny location and take note of its growth. If its stems are stretching out wide, the plant is trying to get more sunlight and should be moved to a brighter area. Outdoor plants can tolerate a little bit of shade, but still should be grown predominately in sun.
Rose plants should be watered often during the growing season, enough to keep the soil moist to the touch. New rose plants that are transplanted to the garden should be watered daily for the first three weeks. Once established, they can be watered as needed. Test the amount of water in the soil by poking your finger about an inch into the soil. If it's dry, water the rose; if not, withhold watering until the soil is dry.
Mini roses prefer a fertile, well-drained soil that's kept moist. Enhance the soil by fertilizing it weekly. Use a fertilizer that's high in potassium rather than nitrogen (which mostly helps leaves grow). A potassium-based fertilizer will help the plant to continue blooming throughout the growing season. Dilute the fertilizer with water so it's at about 1/4 strength.
If you decide to grow mini rose plants indoors, you will probably have to increase the humidity in the plant's environment. Simply place the rose container on a tray with pebbles and water. The water will evaporate and send humidity up to the plant, while the pebbles help to keep the pot from sitting in the water. Consider running a cool-mist vaporizer occasionally in your house.
Pests such as white flies and spider mites can become a problem for indoor mini rose plants. Help prevent the problem from occurring by wiping the foliage of the plant weekly with a damp cloth or by misting it with a spray bottle. If your plant still gets an infestation, treat it by applying an insecticidal soap or spraying it with a mixture of rubbing alcohol, water and dish soap. Keep infested plants away from healthy plants to keep the problem from spreading. Remove heavily infested leaves and dispose of them if necessary.