Growing Tips for Helianthus Sunflower ‘Sunfinity’
Editor’s Note: Each month, the Greenhouse Grower varieties team chooses one noteworthy variety we think is worth bringing to your attention. Then we share growers’ and breeders’ perspectives on the best ways to produce it successfully at your operation. This month we feature Helianthus ‘Sunfinity’ from Syngenta Flowers.
Helianthus ‘Sunfinity’ is Greenhouse Grower’s Industry’s Choice pick for 2017, as well as the Readers’ Choice winner. This annual sunflower is a profuse bloomer with strong branching that produces multiple flowers per plant from spring to fall.
Gardeners can cut the blooms for use indoors with no mess and without affecting the plants’ performance in the landscape or patio containers. Sunfinity Sunflowers are pollen free, but they still produce nectar that attracts beneficial insects. Unlike traditional short-day sunflowers, Sunfinity sunflowers are facultative long-day plants that offer fast crop times well-suited for late spring and early summer production.
Tim van der Hengst, Head Grower at South Central Growers (SCG) in Springfield, TN, has been working with Sunfinity sunflowers for the last year with good success. The sales team at South Central Growers reported 90% sell through of the product the first week at retail.
van der Hengst says growers need to make sure that plants are receiving long days, as this will provide quicker blooming and less plant growth regulators (PGRs) will need to be applied before shipping. During production, he says he recommends keeping the media moist and applying PGRs at the correct times. If plants get too tall, pinch them back and reapply PGRs at a higher rate. The plants will finish out just fine.
van der Hengst’s Recommendations for Growing Sunfinity Sunflowers Successfully:
Irrigation: Sunfinity sunflowers take a lot of water. Keep them moist at all times. It is important not to let plants wilt because this will cause yellowing of lower leaves and reduce quality at time of shipping.
Fertilizer: Use a well-balanced fertilizer at 80 to 100 ppm nitrogen constant feed.
Growing Media: South Central Growers (SCG) uses a 70% peat, 30% HydraFiber mix.
Planting/Scheduling: Plug time is four to five weeks. Finish time is seven to eight weeks.
Propagation: South Central Growers produced Sunfinity in an 88-strip tray, with a 4-week total plug time from sow to transplant. van der Hengst says applying an early plant growth regulator soil drench helps avoid initial stretch of the seedling. Growers at SCG applied 2 ppm Piccolo 10xc on Day 2.
Lighting: It is necessary to produce Sunfinity sunflowers in early season under short-day conditions. Make sure to provide 14-hour days.
Pinching: Pinch plants to four to five leaves. This can be done before or after transplant, but it needs to be done within a week after transplant.
Plant Growth Regulators: Use 3 ppm Piccolo 10xc at one week after transplant. Follow with 5 ppm Piccolo 10xc 14 to 21 days later. Growers can reduce the second application rate if they produce plants earlier in the season. Also, 30 to 40 ppm Piccolo Sprays or B-Nine at 2500 to 3500 ppm before shipping can help keep head stretch to a minimum.
Pests: Thrips can be an issue later in the season. Watch closely for them as the flowers start to open.
Diseases: SCG did not experience any issues with disease. Growers preventively drenched the crop with a Mefenoxam and Emblem tank mix as a media drench two weeks after transplant.