Vibrant, Ever-blooming Catharanthus

Alison Strate

If you weren’t already madly in love with Suntory genetics, you will be now. The recently introduced Soiree Series of catharanthus hybrids from Suntory were among the favorites at California Spring Trials this year. These outstanding plants have an excellent growth habit with a stunning floral display in vibrant hues of pinks and purples. They bloom from the start of spring with warm sunny days until the beginning of the first frost in the fall. This series enjoys the heat and doesn’t mind it when water is a bit scarce.

Pictured: Soiree Crown Pink Catharanthus

They perform best in well-drained soils, especially when planted in containers. The entire collection is self-branching with a tight, compact habit requiring no mechanical or chemical pinches ever! Phenomenal flower coverage with glistening green foliage makes these annual vincas outperform all others. The bright, attractive flower petals are irresistible to pollinators, especially hummingbirds and butterflies. The Soiree Collection is a must have for every landscaper, homeowner or greenhouse grower. You’ll never have to worry about leggy vinca again.

The Soiree Series is broken into three sub-series categorizing them by habit and size. The first of the three sub-series is the Soiree Crown. It includes Soiree Crown Pink and Soiree Crown Rose. They have gorgeously ridged petals shaped like a queen’s crown. These regal gems will light up any garden with their full flower coverage, vivid, eye-drawing colors and deep, glossy, green foliage. These self-branching beauties are compact, averaging 16 in. in height and an impressive 30 in. wide.

The next sub-series is Soiree Double. It includes Soiree Double Pink and Soiree Double White. These are the most unique annual vincas we’ve seen yet. The blooms have two distinct layers of frilly petals, which will light up any garden. They’re very compact, averaging 14 in. in height and 28 in. wide.

Last is Soiree Ka·wa·i·i consisting of Soiree Ka·wa·i·i Pink, Soiree Ka·wa·i·i Coral and Soiree Ka·wa·i·i Lavender. These extremely compact, micro-blooming vinca averages less than 10 in. in height and have an average width of 18 in.

Catharanthus is valued for its moundy and bushy habit. The dark foliage makes the flowers pop in any setting. But what’s even more impressive is how nicely these plants fill out beds and containers. They do well in the landscape as a border, filler or even in mass plantings. They’re also perfect for containers and hanging baskets, either as standalone or in combinations. Don’t be afraid to mix these with other varieties, as they mix well with others. Whether you’re a grower, retailer, consumer, landscaper or gardener, catharanthus is the perfect choice for a new crop this coming season.

Cultural information
Zone: 8 to 11
Soil type: Well-drained, nutrient-rich media
pH: 5.4 to 5.8
EC: 1.0 to 1.5
Fertilization: 200-250 ppm N
Light Requirement: Very high (6,000 to 9,000 candles)
Temperature: 60 to 70F (15 to 21C) night, 75 to 85F (23 to 29C) day
Watering: Moderate to dry

Finish time
4-in. = 4 to 8 weeks
6-in./1-gal. = 6 to 10 weeks

Production information
Transplant liners early spring through early summer, maintaining adequate temperature for optimal root development—70 to 75F (21 to 23C).

Upon receiving liners, plant one liner per pot in a disease-free, well-drained soilless media. Thoroughly water newly planted liners; soil moisture should be moderate and avoid saturation. After watering, apply a broad-spectrum fungicide.

Provide high fertilizer levels of 200 to 250 ppm nitrogen, including micronutrients at a constant feed: 20-10-20 with micros is recommended.

Maintain a pH of 5.4 to 5.8 throughout production. Start with an EC level of 0.8 in Week 1 and then increase to approximately 0.8 to 1.0 for Week 2. Week 3 to finish: increase EC to 1.0 to 1.5. Using the “pour-through” method to obtain EC readings is recommended.

Pinching isn’t recommended for this crop. Also, no plant growth regulators (PGR) are needed.

The recommended pest and disease control method is to use general and preventative measures correlated with a well-thought-out Integrated Pest Management program. In addition, be mindful of whiteflies, aphids, fungus gnats and red spider mites, as they’re known for being common pests to this genus. Botrytis and root rot are two known common diseases that can affect this genus. GT

Alison Strate works in the Marketing Department for EuroAmerican Propagators.