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SUPERNOVA® Liner Culture Guide

Supernova® liners have been treated to provide a blooming, salable plant in a 4" – 6" container in four to six weeks. While not recommended for hanging baskets or uprights, some growers use them for better flower coverage for early season plantings.

Treatments given to Supernova liners to control vigor are temporary and will lose effectiveness in three to six weeks, depending on growing conditions.

As a general guideline, follow the cultural guidelines and the growth regulator information below for helpful tips on growing Supernova liners. More specific information can be found on Four Star’s individual variety culture sheets.


pH: 5.8 – 6.2. For Superbells® Calibrachoa and Supertunia® Petunia, maintain a lower pH of 5.5 – 5.8.
EC:(2:1 extraction method) .5 – .8
As is true with all Proven Winners®, soil pH and EC levels must be properly maintained.


Supernova liners grow and perform best at an average temperature of 65 – 68 F. Colder temperatures are possible but will delay flowering. Angelface® Angelonia do not flower well below 68 – 72 F.


Containers grown from Supernova liners should be kept moderately moist, but not saturated. More frequent, lighter watering is best, as over-watering and fertilization encourages vegetative growth and flower delay.


Placing in the brightest greenhouse location available is recommended. Low light and warm temperatures will produce a soft plant that grows together rapidly, produces fewer blooms, and may require more PGR (plant growth regulator) treatments. Early season plantings flower best when given continued long days via either daylength extension or night interruption lighting.


None is required or recommended. This would remove the initiated flowers.


It is not recommended on most Supernova varieties as initiated flowers would be aborted. However, Nemesia flower very readily and often benefit from one application of 500ppm four to six days after planting.


Certain varieties within a genera may require different growth regulator treatments, depending on plant size and vigor. Under Four Star Greenhouse growing conditions, we use this chart as a guideline. These rates are based on ½-GL of solution per 100 square feet for sprays. Follow recommended levels for drenches, based on container size. Do not apply under bright, sunny conditions, as this can cause leaf burn.

A Growth Regulator Treatment Guide is shown on the following page.

Growth Regulator Treatment Guide

Growth Regulator Treatment Guide

Note: These are Four Star Greenhouse recommendations when grown indoors, under glass, in Michigan with greenhouse temperatures between 65 and 68 F. Time of year, southern location, warmer temperatures or lower light levels could require more growth regulators. Cooler temperatures may require little to none. This information is provided as recommendations only. Please adjust as necessary, based on your geographic location and growing environment.