Blue LEDs

[RogerRoger]

I am interested in using LEDs to see if they are any good for growing some test plants (VFTs) in my cellar.

I have obtained two regulators for driving two strings of four 3 Watt blue LEDs (using a 19 volt laptop power supply). Before I order the LEDs I would like to ask if anyone has experimented with them and do I need to use Red LEDs as well ?

 

[Av8tor1]

yes, you need other wavelengths besides just blue... there are tons of research on the subject.

Photosynthesis is only one of the concerns, you also have accessory pigments, wavelengths that are used by beneficial organisms, wavelengths that inhibit phytopathogens etc. etc etc.

Red, Far Red, Orange and even Green have been shown to be of use.
Current research is using at least 5 wavelengths (which is really "white")

(White, high power, high CRI LED's are now available.... but owie, not cheap)

Here is a great NASA lecture on using LEDs for plant growth, its a little dated but still excellent.

http://bluegrasscarnivores.com/research1/ledmov.mov

You can supplement with your blues if you want, but by themselves they will not be enough for proper plant growth and long term health IMHO.

YMMV,
Av