dik, to je divne ze tie rastliny v podstate v darkroome bez UVecka vyrastli na pekne planty

toto by ma zaujimalo ako to je mozne

OK uz som si odpovedal:

how is it possible that plants can grow without UV A/B in a dark room without windows only on stock lightbulbs?

Short answer: most plants don’t actually need UV light to grow.

What they really need is light in the visible spectrum—especially red and blue wavelengths—because that’s what drives Photosynthesis. Standard “stock” lightbulbs (like LEDs or fluorescents) emit plenty of visible light, even if they produce little or no UV.

Here’s what’s going on:

1. Photosynthesis uses visible light, not UV
Plants mainly absorb:

Blue light (~400–500 nm) → supports leaf growth
Red light (~600–700 nm) → supports flowering and energy production

UV-A and UV-B sit outside this main usable range. They’re not essential for the core energy process.

2. UV is more like a bonus, not a requirement
Small amounts of UV can influence things like:

pigment production (e.g., deeper colors)
stress responses
production of certain protective compounds

But plants can complete their full life cycle without it.

3. Regular bulbs still provide usable light
Even a basic LED bulb emits enough red and blue light for plants to survive and often grow reasonably well—especially low-light plants like pothos or snake plants.

4. Intensity and duration matter more than UV
If plants are doing okay under room lighting, it’s usually because:

the light is on long enough (e.g., 10–16 hours/day)
the bulb is close enough to the plant
the plant species tolerates low light

If you tried to grow something demanding (like tomatoes), a normal bulb probably wouldn’t cut it—not because of missing UV, but because it lacks intensity.

So: plants in a windowless room under regular bulbs aren’t breaking the rules—they’re just using the part of light they actually need.