Grow Light for Pansy Seedlings: Cool Bright Starts
A grow light for pansy seedlings works together with a cool room. Iowa State University Extension notes pansies prefer 55 to 65 F and can become lanky with warm temperatures or too little light. Bright light close overhead plus cool air gives compact starts ready for the garden.
The short answer
Hang the light 4 to 6 inches above the seedlings, as University of Minnesota Extension suggests, plus run it 16 to 18 hours a day. Illinois Extension advises 18 hours at most. Grow pansies at 55 to 65 F. Sow 8 to 10 weeks before planting outdoors.
How much light do pansy seedlings need?
University of Minnesota Extension suggests seedlings sit 4 to 6 inches below the light, moved up as they grow. It suggests 16 to 18 hours of light a day for seedlings. Illinois Extension uses a timer plus caps seedlings at 18 hours. University of Maryland Extension notes window light is seldom enough for sturdy seedlings.
| Factor | Guide | Source |
|---|---|---|
| Light height | 4 to 6 inches | University of Minnesota |
| Hours per day | 16 to 18 | University of Minnesota |
| Hours per day | 18 at most | Illinois Extension |
| Growing temperature | 55 to 65 F | Iowa State University |
| Sowing time | 8 to 10 weeks before planting | Iowa State University |
Source: University of Minnesota Extension, Illinois Extension plus Iowa State University Extension.
Why do pansies need a cool room?
Pansies love cool spring plus fall weather, notes Iowa State University Extension. It notes they tolerate light freezes very well. Warm temperatures can make the seedlings lanky, even under good light. A cool room or basement near 55 to 65 F suits pansies better than a warm windowsill.
When should pansy seedlings go outside?
Iowa State University Extension advises sowing pansies 8 to 10 weeks before planting outdoors. North Carolina State Extension notes pansies prefer full sun to part shade in moist, well drained soil. It suggests fall planting for winter plus early spring blooms. Ease seedlings into outdoor conditions before planting.
How to: step by step
- Work back 8 to 10 weeks from your planting date.
- Sow seeds into a seed starting mix.
- Hang the light 4 to 6 inches over the tray.
- Set a timer for 16 to 18 hours.
- Hold the room around 55 to 65 F.
- Harden off, then transplant into full sun to part shade.
Troubleshooting
Lanky seedlings: too little light or a warm room. Lower the light plus cool the room.
Leaning seedlings: light only from a window. Move them under a grow light.
Seedlings touching the light: plants grew taller. Raise the light to 4 to 6 inches above the tips.
For related reading see cannabis seedling light schedule, leggy cannabis seedlings plus hardening off cannabis seedlings. Kind Seed Co also stocks cannabis seeds.
Sources
- Growing pansies and violas, Iowa State University Extension
- Viola x wittrockiana, North Carolina State Extension
- Lighting for indoor plants and starting seeds, University of Minnesota Extension
- Supplemental lighting for indoor seed starting, Illinois Extension
- Grow lights for starting seeds indoors, University of Maryland Extension
FAQ
When should pansy seeds be started?
Iowa State University Extension advises sowing pansies 8 to 10 weeks before planting outdoors. North Carolina State Extension suggests fall planting for winter plus early spring blooms, so the sowing date depends on your planting season. Count back from that date and give the seedlings the full stretch under lights.
How far should the light be from pansy seedlings?
University of Minnesota Extension suggests 4 to 6 inches between seedlings and the light. It advises moving the light up regularly as the plants grow. A light hung far above the tray gives weak, lanky growth, so check the gap every few days and adjust the chains as needed.
How many hours of light do pansy seedlings need?
University of Minnesota Extension suggests 16 to 18 hours a day for seedlings. Illinois Extension advises no more than 18 hours. A simple timer runs the light on the same schedule each day. That gives the seedlings a steady dark period without anyone needing to remember the switch.
What temperature do pansy seedlings like?
Iowa State University Extension notes pansies prefer cool conditions of 55 to 65 F. It notes warm temperatures can make them lanky, even when light is adequate. A cool room or basement often suits pansy seedlings better than a warm spot. Cool air plus close light gives compact starts.
Why are my pansy seedlings lanky?
Iowa State University Extension notes pansies become lanky with warm temperatures or inadequate light. Lower the grow light to 4 to 6 inches above the tips, check that the timer runs 16 to 18 hours, then cool the room toward 55 to 65 F. New growth should come in shorter.
