- Calendula Uses:Pot, border and mixed container
- Garden height:12″ / 30 cm
- Crop time:9-10 weeks
- Sowing method:1-3 seeds per plug
- Germination*:5-10 days at 70 °F (21 °C), cover seed lightly with vermiculite after sowing.
- Calendula Growing On:Transplant plugs after 2-3 weeks. Grow on at 50-55 °F (10-13 °C). Calendulas are cool weather plants that are best produced for spring or early fall sales.
- Media:Use a well-drained, growing substrate with 10-30 % clay, 0-15 % parts (e.g. bark, sand, perlite), 1-1,5 kg /m³, complete balanced fertilizer. Iron-chelate, micronutrients, pH 5.8-6.5.
- Temperature:Grow at 10-15°C (50-59 °F). Calendula does not grow at temperatures below 8°C (46 °F). A cool cultivation in early spring in polytunnel or cold greenhouse is possible.
- Fertilization:High fertilization levels are required. Fertilize the crop weekly with 100-200 ppm nitrogen (at 2 kg/m³ slow release fertilizer in substrate), using a complete balanced fertilizer. Avoid high ammonium and high nitrogen levels. High nitrogen levels cause delay in flower initiation and smooth stems. Prevent magnesium deficiency by applying magnesium sulphate (0,025%) 1-2 times and in case of iron deficiency apply Fe-Chelate for 1-2 times.
* GERMINATION STAGES (FROM SEED TO FINISHED YOUNG PLANT)
Calendula Stage I Starts with the radicle breaking through the testa. The roots are touching the medium. Ends with fully developed cotyledons.
Stage II Starts from fully developed cotyledons. Ends with the fully developed true leaf or true leaf pair.
Stage III Starts from the fully developed true leaf or true leaf pair and ends with 80% of the young plants being marketable.
Stage IV All young plants are ready for sale and in the process of being hardened off. This stage lasts about 7 days.
The cultural recommendations are based on results from trials conducted under Central European conditions. Different conditions in other parts of the world may lead to deviations in results achieved.