April 2004

Sunflor Pot Carnations By Joe O’Donovan

In these increasingly challenging times, growers are constantly searching for that perfect product — high retail sales value, low cost per square foot, low energy requirements, low PGR needs, yet still programmable for shipping. Often this search results in looking at new genetics of old favorites. And dianthus has been a favorite for many years.

Sunflor has fully double flowers and is available in seven vibrant colors — White, Pink, Dark Pink, Red, Bright Red, Rose and Scarlet. This series has a tight bloom window for simple planning and bench run production.

In cooperation with, and under the supervision of The Netherlands General Inspection Service for Ornamental Plants, all Sunflor carnations cuttings sent to Oglevee are inspected and certified as being disease and virus free. Oglevee certified clean stock production system then takes over to produce culture virus indexed (CVI) cuttings. Stock plants are grown in North America to ensure availability and cleanliness.

Bred specifically for use as pot plants, Sunflor requires little to no growth regulators to produce a compact habit. With a tight bloom window and the ability to grow up to eight plants per sq.ft., Sunflor is perfect for consistent, profitable production. It is also very cold tolerant, allowing cool production temperatures for cost savings.

Sunflor can be grown in different ways. As an unheated crop, cuttings can be planted September-November. Cuttings are pinched once, 4-6 weeks after planting. Depending on the planting time, flowering starts in February, March or April.

Sunflor can tolerate a light night frost. Some heat will reduce the crop time to about three months. Plants are grown at 50-59º F with sufficient light and carbon dioxide dosing. Following this regime can provide April flowering. Costs per square foot are minimized by the ability to grow at a high density.

Spacing. At the start of the season, plants should be grown pot tight. The density can be up to 11 plants per sq.ft. for 31?2-inch pots. Spacing is widened only once, when the plants touch. The plant density then varies from 7-8 plants per sq.ft. The growing temperature will influence the growth speed. The recommended minimum night temperature in winter is 41-46º F. Day temperature in spring should be increased to between 50-59º F depending on light intensity. Adding carbon dioxide to an optimum level of 1,000 ppm improves quality.

Lighting. The production and development of flower buds is improved under long-day conditions. Extended day length can be obtained by lighting all night, or with a 3- to 4-hour night break, for 10-14 days. Lighting can start as soon as the plants have several shoots with at least 6 projecting leaf sets. Extended day length may result in stretch, especially for crops aimed at spring harvesting.

Feeding and Watering. A fertilizer that includes magnesium is recommended. Initial fertilization with calcium nitrate and 10-52-10 is also recommended. Limit maximum feed concentration to 2.0 EC. While Sunflor requires regular watering, too much water can cause the crop to grow too tall. Make sure the crop dries as quickly as possible. Watering should take place in the morning. Overhead watering during production is no problem, provided clean water is used. However, be careful with open flowers and ensure that the foliage dries quickly.

Autumn crop. Cuttings planted in June-July can be scheduled to flower September-October, at which time period 6- to 61?2-inch pots can be used. The crop can be pinched twice, which extends crop time 4-6 weeks.