Cultivation tips for Asian primroses and ranunculi in August/September 2018

Primroses and ranunculi will soon need potting on for the coming season. We have compiled a list of tips to help you optimize the cultivation process.


Use plenty of well-draining and airy substrate, pH 5.5-5.8. Add an NPK fertilizer with an EC, nutrient content of 0.5-0.8 mS/cm. Use sufficiently composted raw materials and/or peat and add a small amount of clay.


During the first two to three weeks after potting on, ensure extra protection against excessive light levels. Use shade netting, a mobile screen or chalk on the greenhouse roof. Aim for a maximum light level of 25-30K lux. The light level can be raised to 40-50K lux as soon as the plants have properly taken root.


Use vegetative fertilizer during the first weeks after potting on, such as NPK 19-19-20 (200 PPM N). Switch to generative fertilizer as soon as the plants fill the pots, for example, NPK 13-4-36 (250 PPM N). Occasionally add some extra iron to your fertilizer.
If you use rainwater, also add extra calcium to your fertilizer. Spring water usually contains sufficient calcium and magnesium. Acidify water with a pH value of above 6.0.
Note: Fertilize the primula obconica with a low Boron fertilizer.

Growth regulation

If the primulas are likely to grow too big, growth can be regulated using propiconazole (25 PPM). The Sprinkles can be regulated with daminozide 85 (B9) 1500 PPM. The Sprinkles Dwarf will most likely not need much regulating, if any.

Crop protection

Regularly scout your crop for diseases and pests. Use sticky traps for timely detection. Consult with your crop protection advisor about which treatments and concentrates are to be used. The primula obconica Touch Me is susceptible to attack by insects. Draw up a plant protection plan against various insects prior to cultivation. In many cases, weekly insect control is necessary.
Should you have any questions regarding these cultivation tips, please do not hesitate to contact us.

Growing Support department, Tel: +31 571 271 717

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