Grow Light for Crossandra: Firecracker Flower Indoors
A grow light for crossandra helps this tropical plant hold its glossy leaves plus salmon or orange flowers indoors. Crossandra is also called firecracker flower.
The short answer
NC State Extension notes crossandra needs bright indirect light, warm indoor air plus high humidity. University of Missouri Extension notes supplemental electric light is usually the easiest way to give plants enough light indoors. Use a full spectrum LED close above the plant on a timer.
How much light does crossandra need indoors?
UF/IFAS notes crossandra can tolerate up to four hours of direct sun per day plus can also grow in partial shade. It makes a fine flowering houseplant given enough light plus moisture. A lamp adds light on dim winter days.
| Factor | Target | Why |
|---|---|---|
| Direct sun | Up to 4 hours a day | Tolerated limit (UF/IFAS) |
| Lamp distance | Plant tips 6 to 12 inches away | Light drops fast with distance (Missouri) |
| Hours with window light | 12 to 14 hours | Supplements daylight (Missouri) |
| Daily maximum | No more than 16 hours | Plants need darkness (Maryland) |
| Air temperature | Above 55 degrees Fahrenheit | Leaves drop when cooler (NC State) |
Source: UF/IFAS, NC State, University of Missouri plus University of Maryland Extension.
Where should a grow light sit for crossandra?
Missouri advises placing most plants with their tips 6 to 12 inches from the light source, since intensity drops rapidly with distance. Hang the fixture so it can rise as the plant grows.
How many hours should the light run?
Missouri notes plants with no outdoor light need 16 to 18 hours a day, while 12 to 14 hours may do if some window light reaches them. Maryland advises no more than 16 hours in total. Run lights alongside window light, per Missouri.
How to: step by step
- Set crossandra in your sunniest window.
- Add a full spectrum LED above the plant.
- Hang the light 6 to 12 inches above the tips.
- Put the light on a timer for a steady day length.
- Watch new growth for color plus spacing between leaves.
- Adjust height or hours as the plant responds.
Troubleshooting
Long, weak stems: low light. Lower the lamp or add hours.
Pale or browning leaves: too much light. Maryland notes excess light turns leaves pale plus brown, so raise the lamp.
Dropping leaves: UF/IFAS notes crossandra sheds leaves once temperatures reach the 50s, so move it somewhere warmer.
For lighting see grow lights for cannabis plus led light distance cannabis. Read grow light timers plus cannabis seeds. Kind Seed Co also stocks cannabis seeds.
Sources
- Crossandra, UF/IFAS Gardening Solutions
- Crossandra infundibuliformis (firecracker flower), NC State Extension Gardener Plant Toolbox
- Lighting for indoor plants, University of Maryland Extension
- Lighting indoor houseplants (G6515), University of Missouri Extension
FAQ
Can crossandra grow under a regular LED bulb?
University of Missouri Extension notes LED plant lights can be made to give the red plus blue light plants need. Household bulbs give less useful light. Missouri also notes high light plants are harder to grow under home lights, so use a plant LED close above the foliage.
Should the light run all night?
No. University of Maryland Extension notes most plants need a period of darkness to develop properly plus advises no more than 16 hours of light a day in total. University of Missouri Extension suggests 12 to 14 hours when some window light also reaches the plant.
Does crossandra need humidity?
Yes. UF/IFAS notes crossandra loves humidity plus its leaves can be misted regularly indoors. NC State Extension suggests setting the pot on a tray of pebbles plus water so the pot bottom stays above the water line. Hold the soil moist but never soggy, per UF/IFAS.
Do plants need a dark period?
University of Maryland Extension notes most plants require a period of darkness to develop properly. It advises lighting them no more than 16 hours a day in total, especially when artificial light adds to natural light. Set a timer so the lamp shuts off each night.
Why do crossandra seed pods pop?
NC State Extension notes the name firecracker flower comes from seed pods that tend to burst near high humidity or rain. UF/IFAS advises trimming stems back after the flowers fade to avoid this. Pinching off faded blooms also encourages new flowers, per both UF/IFAS plus NC State.
