If I keep the regular (so called warm white) night lamp during nights above my Echinacea angustifola and Rudbeckia hirta seedlings (like pictured in the photos), would it be helpful or harmful for seedlings?
The lamp is 3W, and doesn't produce any significant heat.
This setup was only for taking photos, I turned off the lights.
Does nothing, Vivid, for the plants. Plants need dark as well as light. These baby plants need acclimation when you want to transplant them elsewhere. I am unable to see your pots clearly, is this soil soggy with water? Looks like you planted more than one or two seeds in each. This might cause problems when you thin to just one or two plants...which you should do now not later....
If you want a night light get a green light. Nice grow room btw!! Allow those little pots of soil to dry out before watering. Too much water will cause fungus and rot.
As mentioned by stormy, your table lamp does nothing for the plants, but it does illuminate the space at night so you can see your seedlings.
If you want to extend the “daylight” hours - so your plants are exposed to more light to help them grow - you should investigate the use of plant grow lights.
LED plant grow lights are the best type, as they are very efficient, require no ballast or reflector, operate at very low temperatures and have a very long life. LED plant grow lights are coloured to emit the most suitable wavelength of light for the healthy growth of plants indoors. (L.E.D. is an acronymn for light emitting diode).
I’d recommend a Google search (or similar search engine) for “LED grow lights” and include your state/region or city. I’d expect you should be provided with a range of suppliers who specialise in LED grow lights for plants... these are often sold by stores specialising in hydroponic and aquaponic equipment.
There is also a lot of YouTube video content that includes reviews and show how to set up LED plant grow lights.
If you have a tight budget, you can make your own plant grow light and again there is a lot of YouTube video content on how to go about this.
Also refer to this SO answer to this SO question “Are household LED bulbs suitable as supplemental light for plants?” for additional information and relevant discussion on the topic.
