‘Stopwatch Cream’ and ‘Stopwatch Orange’ are day neutral and will flower early enough for spring sales. Their habit is controlled, making them a good choice for growers who wish to produce neat, tidy packs. Very heat tolerant, flowers of Stopwatch varieties will remain open longer into the evening than other portulacas.
Germinate at 70-75° F. Do not cover seeds, as light aids germination. Growers should allow eight to 10 weeks from sowing until flats are in bloom. They can be sown directly into flats or transplanted in clumps. Maintain uniform, but not overly wet, moisture levels.
Growing on, fertilize every two to three irrigations with 50- to 75-ppm nitrogen at Stage 2. Increase to 100-150 ppm through Stage 4. Avoid excessive use of ammonia-based formulations. Allow substrate to dry moderately between irrigations from Stage 2 on. Gradually increase light levels from 2,000 foot-candles at Stage 2 to as much as 5,000 foot-candles at Stage 4.
When finishing, fertilize at 150- to 200-ppm nitrogen every other irrigation. Maintain temperatures above 70° F for best results. Portulaca does not respond well to constantly moist media; allow to dry thoroughly between irrigations.