Professional Growers

Potunia
Culture and Production recommendations

Unrooted Cuttings

• Open boxes as soon as cutting are received. If necessary, cuttings can be stored overnight at 45°-50°F (7-10°C). Mist cuttings if they are wilted.
• Use a disease-free rooting medium that is well-aerated with a pH 5.5-6.0 and EC less than 1.5.
• Good “soil to stem” contact is important for petunia rooting. Make sure the dibble hole is not too large.
• After sticking, water the cuttings uniformly to help “seat” the cuttings.
• Temperature should be maintained at 60 °-65°F (15-18°C) day and night
• Bottom heat at 70°-74°F (21-23°C) will enhance and improve uniformity of rooting.
• Mist should be reduced as roots form. Excessive misting results in iron deficient chlorotic foliage and increased disease pressure.
• During rooting, a light level of 1,500-2,000 f.c. (16,000-21,500 lux) is best. As cuttings establish roots, gradually increase light level to 3,500-4,500 f.c. (37,500-48,500 lux).
• Fertilize cuttings with 100 ppm N as soon as roots are visible. Fertilizer can be increase to 150 to 200 ppm N as roots develop.
• Cuttings can be pinched in the liner stage to reduce stretch, increase basal branching, and remove early flowers.
• Potunias™ are naturally compact, however, B-Nine or Dazide (Daminozide) can be applied once at 750 ppm to control stretching and maintain uniformity of cuttings in the liner stage.

Account for your local weather conditions and adjust the recommendations accordingly. It is important not to over water as that will delay root development, cause an iron deficiency, and increase chances of disease.

Transplanting Rooted Cuttings

• Use a disease-free, well-aerated root medium with a pH of 5.5-6.0.
• Rooted cuttings should be watered well before transplanting. Initial watering is improved if the finish container root medium is moistened before transplanting.
• Rooted cuttings should be level with the new container medium in to limit drying out and wilting of newly planted liners.

Growing a Quality Plant

• Gradually increase liquid feed to 250-350 ppm N with a complete fertilizer containing adequate micronutrients. Fertilizers with increased iron are best.
• Chelated iron applications can be made if needed to maintain green leaf color. Maintain a root medium pH of 5.5-6.0 as iron uptake is reduced at higher pH’s.
• Maintain a root medium EC of 1.5-2.8.
• Manage water and humidity to reduce occurrences of diseases. Do not over water as it can also cause iron deficiency.
• Use a growing temperature of 55°-70°F (13-21°C) day and 55°-60° F (13-15°C) night with good circulation for best growth. High temperatures cause excess stretching and weak growth.
• Light levels should be 5,000 to 8,000 f.c. (53,500-86,000 lux) for improved plant form.
• Pinch or apply Florel (ethephon) 1-2 weeks after transplant. Shearing works well but can delay flowering 2-3 weeks. For Potunias™ we suggest 150-200 ppm of Florel applied only once.
• It is generally not necessary to apply additional PGRs to Potunias™. However plants grown at night temperatures greater than 60° F (15°C) and/or low light can stretch therefore additional pgr applications may be needed. If needed, use 0.5-1.0 ppm Bonzi, Paczol, or Piccolo (paclobutrazol) drench when plants have reached mature size. Do not apply at higher rates or as a spray because plants can be distorted.

Providing high light, cool temperatures and a negative DIF will also reduce stretch. If new growth is yellowing, check pH and iron levels. If mature leaves are yellowing: check EC, N, and Magnesium levels.

Scheduling

These scheduling guidelines must be adjusted for specific greenhouse environments and growing techniques.

Registration of chemicals can vary among states and Canada. Always check local registrations and carefully follow label recommendations. Chemical recommendations are only suggestions that need to be confirmed by the grower.