Are Dipladenia Perennials or Annuals?

The question of whether a Dipladenia is a perennial or an annual has a nuanced answer. Native to tropical regions of Central and South America, this plant is technically a perennial. This means it has a natural lifespan that extends beyond a single growing season. However, its ability to survive year-round is entirely dependent on the climate it’s grown in. For many gardeners, its classification is determined by local winter temperatures.

Defining Dipladenia’s Growth Cycle

A perennial is a plant that lives for more than two years, often growing and flowering over many seasons. Conversely, an annual completes its entire life cycle, from germination to seed production, within one year and then dies off. Dipladenia falls into a category often called “tender perennials.”

These plants are true perennials in their native, warm habitats but lack the hardiness to survive freezing temperatures. When exposed to a frost, the plant’s cells can be damaged, leading to its death. This temperature sensitivity is why a single plant species can be grown as a perennial in one garden but treated as an annual in another just a few hundred miles away.

Growing Dipladenia as a Perennial

In regions with mild winters, Dipladenia can be grown as an evergreen perennial, keeping its glossy leaves year-round. These areas are identified as USDA Hardiness Zones 9, 10, and 11. Gardeners in these climates can plant Dipladenia directly in the ground or in large containers, where it will return year after year.

Within this range, its winter behavior can vary slightly. In the warmest zones, like 10 and 11, it may flower on and off throughout the year with minimal dieback. In the cooler end of its perennial range, such as zone 9, the plant might experience some leaf drop or die back to the ground after a cooler spell. However, its root system will remain alive, pushing out new growth as the weather warms in the spring.

Using Dipladenia as an Annual

For gardeners living in areas colder than USDA Zone 9, Dipladenia is most commonly treated as an annual. Gardeners purchase the plants in spring, enjoying their prolific, trumpet-shaped flowers through the summer and into the fall. Once the first hard frost of autumn arrives, the plant’s life in the garden comes to an end.

Gardeners will simply allow the frost to kill the plant, and it is often removed from the garden at the end of the season. The following spring, new plants are purchased to repeat the cycle. This approach provides a reliable burst of summer color for sunny decks, patios, and garden beds.

How to Overwinter Dipladenia

Gardeners in colder climates who wish to keep their Dipladenia for multiple years can bring it indoors for the winter. This process, known as overwintering, involves moving the plant to a protected environment before the first frost. When nighttime temperatures consistently dip toward 50°F (10°C), it is time to prepare the plant for its move inside, as these temperatures can stress the plant.

Before bringing it indoors, inspect the plant for pests like aphids or spider mites. Prune the plant back by about one-third. This makes it a manageable size and encourages bushier growth in the spring.

Once inside, place the Dipladenia where it can receive bright, indirect light, such as near a south-facing window. During the winter months, the plant will enter a period of dormancy, and its growth will slow considerably. Its watering needs will also decrease; water only when the top inch of soil is dry.

Fertilizing should be stopped completely until spring. When the danger of frost has passed in the spring, the plant can be gradually reintroduced to the outdoors.