Tips on Torenia

Paul Gaydos

Torenia, also known as wishbone flower or bluewings, is a notable heat-loving plant. It can be grown in pot sizes ranging from 4-in. to gallon containers and is suited for hanging baskets and mixed containers, as well. A Zone 9-11 plant, it’s a year-round color item if you’re lucky enough to have a mild winter.

Culture
Rooting. Torenia is fairly easy to root and will take 21 to 28 days before being ready to transplant. Maintain soil temperatures of 70F to 75F (21C to 24C). Bottom heat is recommended as well as rooting hormone, IBA at 2000 ppm. Stick one cutting per cell. If cuttings start to stretch, use Cycocel or B-Nine at 1000 to 1500 ppm. Maintain higher light levels in propagation and try to keep torenia separate from crops that require a lot of water.

Growth regulators. The best way to control growth on torenia, like most crops, is with the environment. Maintain high light and warm temperatures, use lower rates of feed, limit the use of ammonium nitrogen and do a soft pinch when needed. If control is still needed, use B-Nine at 1500 to 2000 ppm as a spray or Sumagic drench at 15 ppm. Don’t use plant growth regulators when flower buds are visible, and never use Florel on torenia.

Crop Times: Pot size Plants per pot Number of weeks
4 in. to 5 in. 1 6

1 gal. 1 to 2 6 to 9
10- to 12-in. basket 3 to 5 10 to 13

Pinching. We recommend one soft pinch at transplant and a second may be necessary in larger pot sizes.
Light levels. Moderate light levels are required, about 5000 foot candles. However, avoid direct sunlight in the summer months.

Temperature. Maintain 70F to 75F (21C to 24C) day temperatures and 65F to 70F (18C to 21C) night temperatures. During the growing cycle, cool morning temperatures help prevent stretch. Torenia can perform well in 95F (35C)-plus temperatures if kept moist and out of direct sun light.

Fertilization. Maintain pH of 5.8 to 6.2 and an EC of 0.6 to 0.9. Use a well-balanced feed at 200 ppm with an extra charge of iron. Occasional leaching is required to prevent soluble salt buildup.

Irrigation. This is the most crucial part of growing or rooting torenia. This plant wants water only when it wants water. Allow torenia to dry moderately between waterings. Overwatering will cause disease and it will remain vegetative. Be careful when you water but don’t let torenia wilt, either.

Pests and disease. Watch for aphids and whitefly. Spray as needed. Powdery mildew, pythium and botrytis can all be controlled with proper crop management, irrigation, airflow and spacing. A preventive fungicide drench is also a good idea after transplant.

Torenia is an easy and fun plant to produce. It looks great in many pot sizes, has great consumer appeal and always has a good sell-through in the market. But keep these five points in mind when growing torenia to ensure your success:

Maintain high light levels but keep plants out of direct sunlight.
Use a well-balanced feed with an extra charge of iron.
Maintain warmer temperatures—70F to 75F (21 to 24C) day and 65F to 70F (18 to 21C) night
Do not over water.
Never use Florel on torenia.

Paul Gaydos is broker and technical suppport manager for GroLink.