Cultural Information Vinca Boa

Plug Production
Sowing/Media: Use a well-drained, disease-free, peat-based plug medium with a pH of 5.8 – 6.0 and EC 0.75 mmhos (saturated paste). Cover seed with coarse vermiculite after sowing to provide dark conditions for better germination.

Germination (Stages 1 and 2): Keep medium uniformly moist and humidity high until seedlings are hooking above covering, then dry down covering to control stretch and improve rooting. Soil temperature should be 75 – 78°F (24 - 25°C), as Vinca like it warm to germinate. Light not required at stage 1. For stage 2 keep light levels <1500 footcandles until cotyledons are open. Germination time is 4 – 5 days.

Stage 3: Soil temperature should be 70 – 72°F (21 - 22°C), no lower. Allow the media to dry down slightly between irrigations for best rooting, height, and disease control. Light levels should be around 2500 - 3000 footcandles. Feed every other watering with 100 – 150 ppm N from 15-5-15, 17-5-17, or 13-2-13. Keep media pH 5.8 – 6.0, definitely < 6.5, and media EC 1.0 – 1.5 mmhos (saturated paste).

Stage 4: Keep soil temperature at 70 – 72°F (21 - 22°C). Avoid cooler temperatures, as they promote poor rooting and increase root rots. Keep on the drier side, with light levels 4000 – 5000 footcandles. Use low NH4 feeds, but monitor media pH closely to keep <6.5. Irrigate and fertilise as stage 3.

Plant Growth Regulators: Not required. If you need to control growth, it can be achieved naturally by drying the media down well between irrigations. For chemical PGR’s it is best to run trials yourself as the effects vary widely depending on climatic conditions.

Crop Time: 5 – 6 weeks for 512 plugs, 6 – 7 weeks for 288 plugs, depending on temperature and light levels. Using HID lights during low light periods will speed up growth due to warmer leaf temperatures.

Common Problems: Pythium, Rhizoctonia, Thielaviopsis, aerial Phytophthora, Botrytis, Alternaria leafspot. A preventative fungicide program is recommended. Upper yellow leaves can be caused by media pH >6.5 or low iron.

Growing on to finish
Container Size: Cell packs, 4.5 inch (11cm) pots and 10 – 12 inch (25 – 30cm) baskets.

Media: Transplant into a well-drained, disease-free, peat-based growing mix with pH of 5.5 – 6.0 and EC 0.75 mmhos (saturated paste). Avoid saturating media with water right after transplanting to control root rots. Use half-saturation technique for watering until roots to sides of container. Do not transplant any plugs showing upper yellow leaves!

Temperatures: Keep daytime temperatures 75°F (24°C) or higher. Night temperatures can be 65 - 68°F (18 – 20°C) no lower. Vinca grows better in warmer temperatures.

Light: Keep light levels as high as possible if ideal temperatures are achievable, 5000 footcandles or higher as a guide.

Irrigation and Fertilization: Do not allow media or foliage to get too wet as this will encourage disease! However, watering lightly but frequently can also create disease problems. It is best to irrigate well and allow media to dry almost to the point of wilting before irrigating again. Fertilise once a week (starting a week after transplanting) with 200-300ppm N (nitrate-form) from 15-5-15, 17-5-17, or 13-2-13, avoid excess phosphorus. Maintain media pH 5.5 – 6.0, definitely <6.5, and media EC 1.0 – 1.5 mmhos (saturated paste). It is possible to fertilize with every irrigation at 150-200ppm N (nitrate form) as long as media pH and EC are maintained as above.

Plant Growth Regulators: Not required. If you need to control growth, it can be achieved naturally by drying the media down well between irrigations. For chemical PGR’s it is best to run trials yourself as the effects vary widely depending on climatic conditions.

Common Problems: Pythium, Rhizoctonia, Thielaviopsis, aerial Phytophthora, Botrytis, Alternaria leafspot. A preventative fungicide program is recommended. Upper yellow leaves can be caused by media pH >6.5 or low iron.

Crop Time: 4.5 inch (11cm) pots (1 per pot) 6 - 7 weeks. 10 - 12 inch (25 – 30cm) baskets (7-9 plugs per basket or 1-3 mature plants in 3.5 - 4.5 inch 9cm – 11cm pots) 11 – 14 weeks. Depending on temperature, and light levels. These times are based on summer production.