Light

Mandevilllas bloom best with at least 6 hours of direct sunlight a day. Morning sun is ideal with protection from afternoon sun that can damage the flowers will have your plant thriving. Growing Mandevilla in containers is a great way to ensure they are getting proper care. You can move the container to the best spot for the time of day.
When growing Mandevillas indoors, keep them in front of a sunny window where it can get at least 6 hours of sun a day.

Water

Mandevilla can handle some drought and still bloom, however, they prefer to be kept consistently moist. When watering, water slowly to allow the soil to soak up the moisture. Try to water when the top layer of soil is dry to the touch. Spraying the leaves regularly will also help the plant thrive.

When indoors, water your Mandevilla every week or so. Check the soil regularly and water when it is dry to the touch.

Fertilizer

Use a liquid fertilizer every two weeks from spring to fall. Or use a slow-release fertilizer every month.