Begonia STARA, MALAGA and IKON Cultural Information

Plug Production
Sowing/Media: Use a well-drained, disease-free, peat-based plug medium with a pH of 5.5 – 5.8 and EC <1.0 mmhos (saturated paste). Use pelleted seed and do not bury seed with initial waterings. No covering is needed.

Germination (Stages 1 and 2): Soil temperature should be 73 – 78°F. Keep medium uniformly moist, almost saturated, with no change in color of soil surface, until first true leaf is halfway expanded. Light levels should be <1500 footcandles. Light will enhance germination and early growth. Germination time will be about 14 days until cotyledons have all expanded.

Stage 3: Soil temperature should be 68 – 72°F. Once first true leaves are halfway expanded, dry off soil surface. Begonia roots are very shallow until that point, so any drying of soil surface before then will cause stunting and uneven growth. Do not dry down below the roots until the roots are to the bottom of the plug cells. Keep light levels 1500 – 3000 footcandles. HID lights will speed up growth during low light periods. Feed every watering with 100 – 150 ppm N from 20-10-20, 15-5-15, or 17-5-17. Begonias like NH4 feeds to expand their leaves. Keep media pH 5.5 – 5.8 and media EC 1.25 – 2.0 mmhos (saturated paste).

Stage 4: Soil temperature can be lowered to 65 – 68°F. Maintain light levels around 3000 footcandles. Practice a good wet/dry moisture cycle, but only water plugs in the morning to avoid burning leaves on sunny days. Feed as needed with 150 ppm N from 17-5-17, 15-5-15, or 13-2-13 to tone plants. Slow down growth by running drier and not feeding, along with cooler temps and high light.

Plant Growth Regulators: Spray with B-Nine (1000 – 2500 ppm) or A-Rest (2 – 3 ppm) as needed, but withhold water and feed first. Do not allow Bonzi drift onto begonia plugs, as permanent stunting will occur.

Crop Time: 8 – 10 weeks for 512 plugs, 9 – 11 weeks for 288 plugs. Crop times can be reduced by 1 – 2 weeks with HID daylength extension during low light periods.

Common Problems: Pythium, Botrytis, algae crusting, fungus gnats and shoreflies, burnt leaves – watering when leaves are too hot from sunny days, uneven growth – too dry too soon after germination, hard curled-down leaves – too dry/not enough NH4 feed/ too much calcium feed/ too high of light levels.

Growing on to finish
Container Size: Cell packs to 4-inch pots

Media: Transplant into a well-drained, disease-free, peat-based growing mix with pH of 5.5 – 5.8 and EC <1.5 mmhos (saturated paste). Do not bury plugs!

Temperatures: Keep soil temperature 65 – 68°F for rooting out, then lower to 63 – 68 F to grow on.

Light: Keep light levels <4000 footcandles. Low light levels promote bigger leaves and faster growth. High light levels promote hard leaves and earlier flowering.

Irrigation and Fertilization: Practice a good wet/dry moisture cycle, but avoid drying below roots until they are down to bottom of container. Drying out too soon will cause stunting and uneven growth. Water begonias in the morning to avoid burning leaves on sunny days. Feed 2x/week with 150 ppm N from 20-10-20, 15-5-15, or 17-5-17. Increase moisture and feed levels if growing under high light levels. Keep media pH 5.5 – 5.8 and media EC 1.25 – 2.0 mmhos (saturated paste). To tone crop, stop feeding and dry down thoroughly before watering again.

Plant Growth Regulators: To control growth, manage moisture, feed, light, and temperature first. Use sprays of B-Nine (1500 – 2500 ppm) or A-Rest (2 – 5 ppm) as needed.

Common Problems: Pythium, Botrytis (spray for Botrytis right after transplanting to avoid early losses due to damaged leaves), fungus gnats and shoreflies, burnt or spotted leaves – watering when leaves are hot from sunny days, big leaves/no flowers – too much NH4 feed and moisture, stunted plants with too early flowering – not enough moisture and NH4 feed but too high light.

Crop Time: 5 – 7 weeks, depending on plug and container size, temperature, and light levels.