Fabulous Fan Flowers: How to Grow Surdiva Scaevolas

Delilah Onofrey, Suntory Flowers

Peak summer, we’re always pleased to see how great Surdiva Scaevolas look in landscapes, containers and even hanging baskets. The demand has never been greater for heat-tolerant annuals. Much of the modern scaevola breeding is modeled after our Surdiva series—compact habit, well-branched with short internodes and saturated color.

Suntory Mixers Disco Diva with Surdiva Scaevola.

Surdiva White has always been our top landscape performer, as bright as snow in beds. Blue Violet and Fashion Pink have set the standard for darker colors. Those have recently been improved for even better floral coverage. New for 2027 is Purple Improved, which looked outstanding in this year’s summer trials.

The six-color range is a uniform series that’s easy to mix and match. Cuttings farms offer combo kits for two Suntory Mixers—Disco Diva (Blue Violet Improved, Fashion Pink Improved and White) and Bluesy Diva (Blue Violet Improved, Sky Blue and White). 

Another favorite is Bee Daring, a multi-genera combo pairing Surdiva Blue Violet Improved with Beedance Painted Orange Bidens and Surfinia Deep Red Petunia. Royalties are bundled as buy 2 get 1 as an incentive.

We also love to plant Surdiva Scaevolas around the base of our new Sun Parasol FiredUp Dipladenias. Kientzler has demonstrated a similar concept, surrounding cyperus with Surdiva. Think of it as a skirt for your thrillers!

If you’re experienced growing scaevolas, you’ll have no trouble producing Surdiva. The main difference is reduced need for growth regulators. Plants are naturally compact. Proceed lightly.

Crop times 

• 4-in. pots (1 liner): 6 to 7 weeks 
• 6-in. pots (1 liner): 8 to 10 weeks 
• 10-in. pots or baskets (3 liners): 12 to 15 weeks 

In general, Surdiva doesn’t need to be pinched. Less pinching is required when plants are grown cool. Plan crops for late spring when daylength increases and temperatures rise. High light and warm temperatures will improve flowering, branching and plant development.
 
Propagation 

• Average propagation weeks is 4 to 5 
• Rooting hormone is optional 
• When sticking, cuttings must be free of flowers and flower buds; these will delay root formation 
• Keep cuttings hydrated; average days with mist is seven to 10; reduce mist as soon as possible 
• Maintain warm soil temperature to optimize rooting—ideal rooting temperatures are 70 to 72F (21 to 22C) 
• Fertilize with 75 ppm N using a Cal-Mag formulation (15-5-15, 14-14-14); increase to 200 ppm N after 10 days 
• Keep light levels at 2,000 foot candles

 
Growing on to finished crop 
Temperature: In general, Surdiva can withstand very high temperatures and loves heat. Maintain day temperatures of 68 to 79F (20 to 26C), night temperatures of 62 to 68F (16 to 20C). Night temperatures lower than recommended will significantly slow the crop and lead to problems with root rot. The use of cool morning treatments will improve plant quality, flower and foliage color, and plant habit, and harden the plants. To avoid delayed flowering, keep average day temperature under close watch and, if necessary, increase night temperatures. 

Surdiva Purple Improved Scaevola. 

Light levels: 4,000 to 7,000 foot candles. The key to growing this crop is high light. Surdiva will flower year-round if light levels are high enough. 

Fertilizer: Increase fertilization rate to 200 to 225 ppm N. Alternate with a clear-water leach every fifth irrigation. Maintain media pH at 5.4 to 5.8 and EC between 2.0 to 2.5. Purpling of foliage can result from low phosphorous and is more prevalent in some colors. Moderate or high levels of phosphorous can cause yellow-red coloring in older foliage. In general, Surdiva tolerates/likes low phosphorous, so we don’t recommend a high phosphorous feed. Surdiva is also a high user of iron, which is why the pH level is lower than other crops. Adding iron chelate to regular feed is recommended in areas with high pH irrigation water. 

Watering: Maintain even moisture levels between wet to dry. In general, avoid drying out or overwatering the substrate, as this will affect plant quality and finishing time. Root system will suffer when conditions change from one extreme to the other. Growing on the dry side means letting the substrate become dry before watering. Keep constantly moist means watering the plants just before the substrate becomes dry. Surdiva should be grown on the dry side. Allow the media to dry between waterings. Be careful to not allow the substrate to dry out completely. Surdiva is sensitive to dry out and tissue will become yellow after a severe dry down. Leaves get very yellow and show symptoms of fertilizer deficiency, but it’s caused by water stress and is irreversible. 

PGRs: Surdiva is naturally compact, so the use of plant growth regulators isn’t necessary or recommended. Pinching can encourage the correct shape and act as a form of growth control. Less pinching is required when plants are grown cool. If PGRs are used, Sumagic spray is recommended at 10 ppm. Also, Bonzi drench at 0.5 to 1 ppm or spray 10 to 20 ppm. 

Disease control: A broad-spectrum fungicide drench is recommended after planting to prevent Botrytis, Rhizoctonia, Pythium and Phytophthora. 
Pest control: Monitor plants for whiteflies, thrips, fungus gnats, shoreflies, leaf miners, aphids and mites.

For more information about Surdiva Scaevolas, visit suntoryflowers.com. We also have a new consumer website: suntorygardenclub.com. GT