Grow Light for Tibouchina: Princess Flower in a Sunroom
A grow light for tibouchina helps princess flower go on forming its purple blooms in a sunroom or bright room. Tibouchina is also called glory bush.
The short answer
NC State Extension lists full sun, 6 or more hours of direct sunlight a day, for princess flower. 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 princess flower need indoors?
NC State Extension notes princess flower likes some shelter from afternoon sun in hot summer areas. In North Carolina it is used as an annual or in containers overwintered in the house or a greenhouse. Missouri notes high light plants need at least 1,000 footcandles.
| Factor | Target | Why |
|---|---|---|
| Light level | At least 1,000 footcandles | High light plants (Missouri) |
| Lamp distance | Plant tips 6 to 12 inches away | Light drops fast with distance (Missouri) |
| Hours of light | 14 to 16 hours | Duration guide (Illinois) |
| Daily maximum | No more than 16 hours | Plants need darkness (Maryland) |
| Soil | Moist, acidic plus well drained | Preferred mix (NC State) |
Source: NC State, University of Missouri, University of Maryland plus Illinois Extension.
Where should a grow light sit for princess flower?
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
- Place princess flower in your sunniest sunroom 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.
Sticky leaves or white fluff: NC State lists scales plus mealybugs as possible pests. Inspect stems plus leaf undersides.
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
- Tibouchina urvilleana (princess flower), NC State Extension Gardener Plant Toolbox
- Lighting indoor houseplants (G6515), University of Missouri Extension
- Lighting for indoor plants, University of Maryland Extension
- Lighting, houseplants, Illinois Extension
FAQ
Can princess flower 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.
Can princess flower take afternoon sun?
NC State Extension notes princess flower prefers full sun but likes some shelter from afternoon sun in hot summer areas. Indoors, a sunroom window plus a grow light fits well. Missouri advises hanging the lamp so plant tips sit 6 to 12 inches below it.
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.
Does princess flower survive winter outdoors?
NC State Extension notes that in zone 8 princess flower will die to the ground in winter but may come back in spring. In North Carolina it is used as an annual or grown in containers overwintered in the house or a greenhouse. Bring pots in before frost.
