Begonia Nonstop Mocca Series
The newest series in tuberous begonias offered by Benary, Nonstop Mocca, offers an interesting twist on an established variety. Like the original green-leafed Nonstop begonias, the Nonstop Mocca series has large (4-inch), fully double flowers in six vibrant colors and a formula mix. A new introduction for 2008 is Pink Shades.
While the large flowers of the Nonstop Mocca series are eye-catching as is, their foliage makes them unique. Pale-green leaf veins contrast the dark-chocolate foliage, making it just as attractive as the series' flowers. With a mounding upright habit, the Nonstop Mocca series creates a dazzling display as a specimen plant in containers, hanging baskets or combination pots.
Varieties in the Nonstop Mocca series have the same high seed quality as the original Nonstops. This leads not only to increased germination, but also an increased uniformity of emergence, improved seedling vigor and a high number of transplantable seedlings of tuberous begonias.
Sow seed on a fine media with good water-holding capacity and drainage. Consistent moisture levels are important for uniform germination. Humidity levels above 95 percent and a media pH range of 5.5-6.5 are important. Germinate at 75-78¡ F. Do not cover seeds, as light is required for germination. Supplemental 24-hour assimilation light provided during Stage I will reduce plug crop time and improve plug quality.
Germination will occur in 7-14 days.
During Stage II, gradually lower temperatures to 70-75¡ F. Maintain Stage I soil moisture and humidity levels. Begin fertilizing at 50- to 75-ppm nitrogen in a well-balanced mix containing calcium nitrate. Do not saturate soils or disturb seeds when fertilizing. Continue assimilation lighting for the duration of Stage II (28-42 days).
Media and Fertilization
Lower temperatures to 68-70¡ F for Stages III and IV. Gradually lower humidity levels, but maintain soil moisture levels avoiding saturated or dry media. During Stage III, increase fertilizer levels to 75- to 10-ppm nitrogen. Stage IV levels may be increased to 100- to 150-ppm nitrogen. Begonias are sensitive to high soil EC levels. Maintain low soil soluble salt levels (0.5-0.75).
Continue assimilation lighting, using either day extension or night interruption lighting. Provide at least 50 foot-candles of light. Total day length of greater than 14 hours is necessary to avoid tuber formation or crop delays. Plugs should be ready to transplant in 8-10 weeks, depending on plug size.
Transplant plugs into finished containers with a well-drained media and pH range of 5.5-6.5. Maintain day length in excess of 14 hours. Continued supplemental lighting will improve plant quality and shorten crop time. Growing temperatures between 68-72¡ F optimize growth and flowering. Fertilize at 150- to 200-ppm nitrate nitrogen in a well-balanced formula. Avoid ammonium nitrogen; increased calcium levels will improve plant quality.
Culture Hints and Finishing
Watering under bright afternoon sun can cause leaf burn. Short days or temperatures below 62¡ F may result in tuber formation and delayed flowering. Powdery mildew can become an issue when relative humidity levels remain very high in the greenhouse. Maintain relative humidity levels of 40-70 percent and adequate air flow through the greenhouse to combat powdery mildew.
Applications of Cycocel (chlormequat chloride) at 150-250 ppm can be used to control growth. Crop time for plugs is 8-10 weeks, 16-18 weeks for 4-inch pots and 20-22 weeks for hanging baskets.