John Heider · Gardenality Genius · Zone 9B · 25° to 30° F
Dipladenia and mandevilla are in the same family. However the Mandevillea are vining plants while the Dipladenia are shorter, bushier plants with more leathery leaves. Dipladenia and mandevilla are often confused with each other because the shape and colors of the flowers on both plants are similar. Mandevillas have a tendency to vine and are usually sold growing in a pot with a trellis that supports the vine(s). A dipladenia plant can also be grown in a pot. However, it is not inclined to vine and grows instead into a small bush. Occasionally, you will find a dipladenia trained to grow as a short vine, but never to the extent that a mandevilla does. The foliage, or leaves, of each plant will let you know which plant you are growing. Mandevilla leaves are longer and narrower than dipladenia leaves, which are wider and somewhat heart-shaped. Dipladenia leaves have a thicker smooth feel, while mandevilla leaves feel rough and textured. The flowers of mandevilla and dipladenia may look the same, but the dipladenia flowers are quite a bit smaller than mandevilla flowers. Originally, dipladenias produced flowers that were light pink and the mandevilla's flowers were uasually shades of red. Today both can be found to have red, white, yellow, and pink blooms.

John Heider · Gardenality Genius · Zone 9B · 25° to 30° F · Comment About Planting
If the plant is to be grown outside in colder regions, it is treated as an annual. Grow in partial shade in a rich, well-drained sandy soil. Organic matter like well-rotted manure, compost or peat moss should be added to the soil, as well as some bonemeal prior to planting. Most in warm climates can grow this plant as a perennial. It seems to do much better in containers than in the ground. It is best to repot the plant each spring in a media consisting of 2 parts peat moss, 1 part packaged potting mix or loam, and 1 part sharp sand or perlite to aid in drainage.

John Heider · Gardenality Genius · Zone 9B · 25° to 30° F · Comment About Feeding
During the growing season in spring and summer, keep the soil evenly moist. Allow the soil to just dry before watering during the dormant season (fall and winter). Fertilize every 2 weeks (if necessary) during the growing season with a fertilizer that is higher in phosphorous such as 10-20-10.

John Heider · Gardenality Genius · Zone 9B · 25° to 30° F · Comment About Pruning
Once the plant has completed blooming, remove the spent flowers. The plant can be kept bushy by pinching out the growing tips occasionally or, by shortening the side branches by cutting back to two buds at the base of the past summers growth in February.