Plant lisianthus after frost. Set a transplant with the crown at the soil line, about six inches apart, and put support in when you plant.
Set transplants after frost, with the crown at the soil line
| Factor | Recommended | Avoid |
|---|---|---|
| When | After the last frost, once nights stay frost-free | Planting into cold, wet ground |
| Plant | A plug or nursery transplant with four true leaves, not a rootbound cube | A plug that has sat in its tray until the roots circle |
| Depth | Crown at or just above the soil line | A deep hole that buries the stem |
| Spacing | About 6 inches apart, in the 4 to 8 inch range | Crowding so leaves stay wet |
Wait until frost has passed, then set lisianthus with the crown at the soil line. Buried stems rot. A rootbound plug often blooms early on a short stem. [1] [2] Sun and watering for the planted crop stay on How to Grow Lisianthus.
When should I plant lisianthus?
Plant after the last frost, once nights stay frost-free. Cold, wet ground stalls the plug. Hardened plants can take a light frost if you can cover a hard freeze.
How to plant lisianthus
Start with a fresh plug, set the crown high, and put the net in while the plants are still small.
- Harden the plants off for a few days. Set each plug so the stem sits completely above the soil, with the crown at or just above the soil line. [3]
- Space plants about six inches apart. That gives air around the leaves and still fills a cutting row.
- Stretch a horizontal net or set stakes when you plant, not after the stems have flopped. The heads get heavy as they bloom. [4]
- Water enough to settle the mix, then keep it evenly moist. Skip the pinch if you want one long cut stem. If you want more, shorter stems, pinch above a leaf pair once the plant is growing.
How deep do I set the transplant?
Set the crown at or just above the soil line. Do not bury the stem in a deep, wet hole.
What fails at planting
Burying the crown is the usual reason a fresh plug rots. A rootbound cube, or a tray left until the plant is starved, often flowers on a short stem. Put the net in at planting, because weaving tall stems through mesh later breaks them.
If a plug wilts after planting, check the crown — a buried stem in wet soil will not recover, so reset a fresh plant high.
FAQ
Should I buy plugs or start seed?
Plugs are the faster home start. Seed needs a 10 to 12 week tray and steady cool light. If you want to sow, start the tray in time.
Should I pinch lisianthus?
Skip the pinch if you want one long cut stem. Pinch above a leaf pair if you want more, shorter stems. Pinching delays bloom and shortens the stem.
Related guides
Recommended plants
References
- [1] Missouri Botanical Garden -
https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=280810 - [2] Johnny's Selected Seeds -
https://www.johnnyseeds.com/on/demandware.static/-/Library-Sites-JSSSharedLibrary/default/dwd7d4d9f2/assets/information/8855-lisianthus-production-tech-sheet.pdf - [3] Utah State University Extension -
https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=3312&context=extension_curall - [4] Old Farmer's Almanac -
https://www.almanac.com/plant/lisianthus
This note is part of Eustoma Guides.
More planting notes by plant are gathered in Planting Guides.
Updated: Reviewed by Bosquelle Editors