Dipladenia Sun Parasol FiredUp

Delilah Onofrey—Suntory Flowers

Patio tropicals are hot and Suntory Flowers has a new type of dipladenia that creates new ways to use them in summer combos and landscapes. 

Sun Parasol FiredUp Orange is the first color in a series that’s naturally freestanding and upright—no trellis required. Slender foliage and leaves support vibrant orange pinwheel-shaped blooms. It’s a great thriller in heat-loving combination planters. (We’ve paired it with Soiree Catharanthus and Surdiva Scaevolas.) It also looks amazing with the more compact Sun Parasol Original Sunbeam, too.

Dipladenia Sun Parasol FiredUp Orange with Sun Parasol Original XP Sunbeam

New for 2026 is FiredUp Coral. This plant is more compact than Orange and the target breeding spec for the series. It presents nicely as a large, full plant, as well as in quarts and gallons for retail. The upright habit works well for high-density production.

Consider FiredUp Dipladenias a new, but familiar, product. Cultural practices are the same as for Sun Parasol Original varieties, but there are stronger height control strategies for FiredUp Orange. Resist the temptation to train it to a trellis. The beauty of the product is that it’s a freestanding thriller.

Transplanting
Now is the time to transplant liners into finished pots—late September/October for April/May sales. Most mandevillas/dipladenias are produced in the South because they require a lot of heat, but many Northern growers also produce them from liners or cuttings. (Cuttings are typically rooted in the summer and transplanted early fall.) Light intensity and temperature are the greatest influencers on timing for spring sales.

Growing times from 72-cell liners:

• 6-in. pots = 1 plant, 8 to 12 weeks
• 8- and 10-in. pots = 2 plants, 14 to 16 weeks
• 12- and 14-in. pots = 3 to 4 plants, 16 weeks

Growing times from 21-cell liners:

• 6-in. pots = 1 plant, 6 to 8 weeks
• 8- and 10-in. pots = 1 to 2 plants, 10 weeks
• 12- and 14-in. pots = 2 to 3 plants, 12 to 14 weeks

The above production timing is based on growing temperatures of 60 to 65F (15 to 18C) nights and 75F (23C) days. In states with lower humidity, like California and Arizona, light shade is beneficial to reduce high transpiration through leaves. In states with high humidity, like Florida and Texas, plants can remain in full sun.

Late summer and fall are build-up times for mandevillas/dipladenias. Northern growers should keep plants in a greenhouse that maintains temperatures of 40F (4C) or higher. In the South, plants can stay outside, but frost protection is recommended to avoid leaf drop. If extreme or abnormal winter weather is forecasted, plan to move crops inside a greenhouse to reduce losses. 

Finishing 
Temperature and light: Sun Parasol is a high-light, high-temperature crop. Shade from plants overhead will slow growth and delay flowering. For active growth, keep day temperatures around 80F (26C) and night temperatures above 60F (15C). Lower temperatures can be used, but plants will be slower.

Keep light levels at 5,000 to 7,000 footcandles. Buds are initiated with 10- to 11-hour days. Supplemental lighting will be required in the north for spring sales windows. High pressure sodium lights or LED lights that increase daylength and light intensity should be turned on in January and February to enhance growth and flower development.

Plants should be grown in full sun during fall, winter and spring. Thirty-percent shade is recommended in the summer to lower greenhouse temperatures.

Most varieties require 11.5 hours of daylight to flower. Extending daylength four hours at sunset during the winter months will produce more vegetative growth, but isn’t necessary for May or June sales.

Media, nutrition and irrigation
Choose peat lite or bark soils that drain well. Most well-drained commercial soil mixes should be satisfactory. Dipladenias should never sit in water.
Ideal pH range is 6.0 to 6.5, although plants can tolerate a pH of 7.0. An EC of 2,500 to 3,000 is the optimum range.

Constant feeding of 125 to 150 ppm and then with clear water every fourth watering works well.

Use a calcium-based fertilizer such as 16-3-16, if water is acidic. If pH of water is more basic, use an acid fertilizer, such as Peters acid fertilizer 15-5-25.

Plant growth does benefit from dressing with a slow-release fertilizer, such as Osmocote or Nutricote, but use at a reduced rate of one quarter to one half the rate if also using liquid feeding.

Keep plants on the dry side when maturing. Mandevillas/dipladenias do not like to be too wet.  

In the spring, when plants are actively growing, increase fertilizer rates to 200 to 300 ppm nitrogen. In areas with alkaline water, add iron chelate to prevent leaf chlorosis.

Pinching and PGRs
Give plants a hard pinch in November or December and a second hard pinch at the end of January or mid-February, depending on when you want them to flower. The last hard pinch should be six to eight weeks before you want them to flower.

Recommended plant growth regulators include B-Nine and Topflor:

• Use B-Nine at 3,500 ppm—two to three applications in March, two weeks apart.
• Use Topflor at 50 ml per gallon of water. Apply once in early March. Spray to glisten leaves. (You don’t want runoff going into the soil.)

Pest and disease control
Good airflow helps prevent foliar leaf spot. Watering in the morning helps. Prevent Fusarium and Botrytis by keeping plants dry in the winter. If plants are held cool and wet overnight, foliage can become necrotic.

After potting, drench with a broad-spectrum fungicide, such as Banrot or Mural at label rates and again four to six weeks later to control any root diseases.

For foliar diseases, such as leaf spot, use Postiva, Pageant or Thiophanate Methyl, such as Cleary 3336 at label rates.

Pests to monitor include aphids, thrips, spider mites, whiteflies and mealy bugs. For mite control, use Epishield or Furious. Both provide excellent control, plus there’s no re-entry interval. They don’t kill eggs, so two to three applications are usually necessary. Phylo and Shuttle also work well. For thrips, Xxpire, Rycar or Pradia are all safe to use on dipladenias. GT

For more information about Sun Parasol mandevillas and dipladenias, visit suntoryflowers.com.