Culture Report: Osteospermum Ostica Series

Danziger’s Ostica series of Osteospermum ecklonis features vibrant and colorful flowers. It has a lovely compact mounded growth habit. This easy-growing, early-flowering series requires no cooling to flower. Plant in full sunlight or half shade in the early spring.

The Ostica series includes 11 colors: Amber (yellow), Bronze (orange), Blue Eye, Burgundy, Meringue (cream), Pineapple (yellow), Pink Improved, Purple Eye, Purple Improved (light purple), Violet and Yellow. Their distinct eyes seem to mesmerize the onlooker. They’re suitable in the garden as a single plant or in a group, as well as a border plant.

ROOTING

Maintain soil temperatures at 72 to 74° F for the first two weeks after sticking. Choose a well- drained medium.

Electrical conductivity (EC) should be 0.80 to 0.90 for weeks one and two and 1.0 to 1.2 for weeks three and four. Maintain pH at 5.8 to 6.2 throughout rooting.

Mist with 50-ppm nitrogen in weeks one and two, and feed 65- to 80-ppm nitrogen in week three. In weeks four and five, target a feed of 100- to 200-ppm nitrogen.

Spray the day after stick with a plant growth regulator such as B-Nine at 3,750 ppm. In weeks three to five, apply a tank mix of 3,770-ppm B-Nine and 10-ppm A-Rest. The combination of B-Nine and A-Rest can be sprayed frequently to stack the nodes and improve branching.

Use a preventive fungicide such as Daconil on the day of sticking and again in week two. Transplant in about five weeks.

PLANTING

Use one plant per 4-inch pot (ready for sales from rooted cutting within eight to 10 weeks. For 6-inch pots, use one to two plants per pot (ready in 10 to 12 weeks). When grown as 10- inch hanging baskets or pots, use three to four plants (ready in 12 to 14 weeks).

PINCHING

Pinching is optional. Pinch early one to two weeks after transplant.

LIGHT INTENSITY

Provide full sun to partial shade, with a minimum of 5,000 foot-candles.

TEMPERATURE

Maintain day temperatures at 64 to 75° F. Aim for cool nights, with temperatures at 45 to 55° F.. Osteospermum blooms in response to night temperatures of less than 55° F. The vernalization period takes about four weeks under temperatures of 45 to 55° F, giving a good bud set and the best flowering potential possible. Flowering grows less in warm summer months.

Osteospermum blooms again in the fall, in reaction to cold night temperatures.

FERTILIZATION

Apply constant feed with a balanced fertilizer (250-ppm nitrogen) that contains average levels of micronutrients with a slightly increased level of iron.

IRRIGATION

Maintain moderate levels of moisture.

MEDIUM

Use a well-drained, disease-free potting mix — peat/perlite mix. Maintain pH at 5.8 to 6.2 and EC at 1.0 to 1.2.

GROWTH REGULATORS

Plant growth regulators may be applied on plants in smaller pots in order to limit their growth. Consider them optional, and not necessary under high light intensities. If you choose to apply them, make one to three sprays of Alar or B-Nine at 2 grams per liter according to required plant size.

PESTS AND DISEASE

Maintain a vigilant scouting and monitoring program to prevent any insect and disease activity. Maintain moderate humidity levels and good air circulation as a preventative. Drench with a broad-spectrum fungicide at liner planting.

Insects to watch for include whiteflies, thrips and leaf miners. Spray preventively.

Monitor for diseases including botrytis and pythium. Use a broad- spectrum fungicide at time of liner planting.

Chanochi Zaks is vice president of marketing for Danziger “Dan” Flower Farm. He can be reached at chanochi@danziger.co.il.