You may have noticed that Lisianthus variety names sometimes (but not always!) contain a numeral, like Lisianthus Megalo 3 Orchid or Lisianthus Celeb 2 Misty Pink. This number indicates the bloom group of that specific variety and shade.
What is a Bloom Group?
Lisianthus bloom groups tell you in what order your Lisianthus will flower. Group 1 flowers first, followed by 2, 3, and 4.
Bloom initiation in Lisianthus is a complicated relationship between day length, light intensity and temperature.
You can plant all groups at one time without issue. Planting 4-6 weeks before your last frost gives them a long cool period in which to establish roots before the heat of summer. Lisianthus are perennial in the wild, and this cool period will simulate winter for them. They can take some light frost after they are hardened off.
If you need to plant in a warmer time of year, choose group 2 or 3 Lisianthus, as they won't be triggered to flower until they have developed a good root system.
Keep in mind that your unique growing conditions will affect bloom timing. It is possible that groups 1, 2, 3 and 4 transplanted on the same date will all bloom at the same time if they feel like it. It is difficult to program Lisianthus for a specific date, even for experienced growers.
If your season is long enough, you can expect a second flush of bloom from your Lisianthus. Some growers even report 2 or 3 additional flushes after the first harvest.
If a Lisianthus variety does not have a bloom group in the name, the breeder has not designated one.
How Day Length and Light Affect Lisianthus Growth
Learn More About Bloom Groups
Bailey covers Bloom Groups (minutes 19:46 to 22:30) in this video class on how to grow Lisianthus. The video will begin at 19:46, but since it's YouTube, there will possibly be a pre-roll ad first.
helpful. But it didn’t explain how light affects things. Does the amount of time in light matter as much as heat outside?
———
Farmer Bailey Inc. replied:
Hi Margaret, thank you for your comment! Lisianthus flowering is driven by three key light-related factors: day length, light intensity, and temperature. Lisianthus behaves as a long-day crop, so longer days (or supplemental lighting) encourage faster bud initiation and earlier flowering, while short days promote slower, more vegetative growth. High light intensity – specifically a high daily light integral (DLI) – also speeds growth and bloom development, whereas the weak winter sun slows plants down. Temperature interacts with light as well: warm conditions accelerate growth, while cool temperatures prolong the crop. In general, longer days, higher light, and warmer temperatures mean faster flowering; short days, low light, or cool weather slow everything down. ~Bobby