July 2003

Scaevola Outback Fan Flower By Frauntene McLarney

Scaevola is a well-known Australian native that thrives ingardens throughout North America from spring to fall, even during the worstheat of summer. The Fan Series (Scaevola aemula) consists of four cultivars infour different colors: Purple Fan, Fan Dancer, Sparkling Fan and White Fan. FanDancer tends to be a little more compact and upright in growth habit ascompared to Purple Fan, which is more trailing. A new pure white, largeflowered scaevola, White Fan, received much attention and was one of the mosttalked-about new cultivars at the 2003 California Pack Trials. It has thelargest flowers in the series and a strong growth habit that is more similar toPurple Fan.

Propagation

Rooting time is 4-5 weeks. Scaevola require rooting hormonefor best rooting; choose one with up to 2,500 ppm IBA or up to 500 ppm of NAAto achieve uniform rooting. Best results can be achieved using vegetativecuttings free of flowers.

Misting requirements for this crop are lower than mostvegetative crops, with cuttings that prefer to be kept a little on the dryside. The crop should be monitored for overwatering during the propagationcycle, as excess moisture will slow rooting and can increase the chance of rootrot and fungus gnat infestation. Soil temperatures of 70-75° F are ideal duringpropagation. Although not required, scaevola benefit from bottom heat duringpropagation by decreasing rooting time. Pinching cuttings once the roots havestarted to grow will enhance overall plant habit and performance aftertransplant.

Growing On

Scaevola prefer a well-drained soil with little to nophosphate added. Like most Australian natives, scaevola is sensitive tophosphorous, which can cause discoloration and foliage desiccation when presentat levels higher than required. Use a complete, balanced fertilizer, low inphosphorus, at 200-250 ppm nitrogen continuous liquid feed. Maintain a soil pHbetween 5.5-6.0 and an EC below 2.0 saturated media extract (SME). If yellowleaves appear, apply iron either through an iron chelate foliar spray or drenchor an iron sulfate drench. Be careful not to apply iron sulfate to the foliage.

Scaevola does well with light levels of 4,000-6,000foot-candles and day temperatures of 70-85° F. Night temperatures should bebetween 68-70° F. Scaevola can be grown with cool crops, but flowering timewill be delayed at average temperatures below 60° F. Scaevola rarely needsany growth regulator. Growing with average temperatures of 65° F will helpkeep plants compact.

One pinch 2-4 weeks after transplant greatly improves flowercount and plant shape. Generally, a mature plant will flower within 5-6 weeksafter pinching. Crop time after transplantis 6-8 weeks for a 4-inch pot, 10-12 weeks for a 61/2-inchpot and 12-14 weeks for a 10-inch pot or basket. Using two cuttings in potsizes larger than 4 inches, and up to four cuttings in 10-inch baskets, willmake a fuller product with high consumer appeal.

Pests and Diseases

Scaevola does not have any significant insect problems,though aphids, scales, thrips and caterpillars have all been found on plantswhen conditions favor these pests. Fungus gnat larvae can be an issue inpropagation and early development, especially with over-misting and irrigating.

Botrytis can affect the flowers and foliage. Maintaininggood watering practices, air circulation and relative humidity go a long way toprevent problems. A preventative spray can be applied, especially afterpinching, to avoid problems with this disease.

Scaevola can also suffer from root and stem rot. This can bemanaged by allowing media to dry between watering and applying preventive soildrenches shortly after transplanting. As a mature plant, scaevola can toleratelight wilting and recover quickly as long as roots are healthy.