The mandevilla is a beautiful vine with large, trumpet shaped flowers that are enhanced by large, glossy puckered leaves To keep your mandevilla blooming there are a few requirements.
Full sunlight and warmth are necessary to help the plant bloom. However, during extended hot spells the plant will need to be watered daily or, if potted, moved into a shady area.
During the growing season your mandevilla will require a high phosphorous (10-20-10) fertilizer every two weeks to encourage blooming. All leaves and no flowers indicate a high nitrogen content
The mandevilla should be planted in a well-draining soil. Allow the soil to dry out before watering. The plant is sensitive to over watering.
Besides the need for well draining soil, the mandevilla needs enough soil. If planted in a container it should have at least 8 to 12 inches of soil. It does not need to be root bound to bloom.
A sun lover, a mandevilla likes it warm and mildly humid. It is a tropical plant. If the temperatures drop below 65 degrees for any period of time, blooming will stop.