New Project: Lettuce under red/blue LED panels @ 5 days

For the second part of the LED grow light experiment, I have placed an identical collection of lettuce seeds into an improvised system identical to the one used in the blue-only LED lettuce experiment.

The seeds have germinated and sprouted with no trouble, and since I kept good records of the lettuce under blue LEDs, we'll be able to compare this setup to the blue setup at the same intervals. As I said before, I would have preferred to do these experiments side-by-side but I had to wait longer for delivery of my red/blue mixed panels.

Photo Update: LED Lettuce @ 20 days

Here is the lettuce specimens that have been growing under blue-only LED's for 20 days now. At this point I think it's safe to conclusively say that these plants are by no means thriving. Under normal light, the plants have a very normal and uniform green appearance (no necrosis or browning/yellowing of leaves), but they have very slender, weak stems which are unable to support the weight of their tiny leaves.

Root development is also severely stunted (not shown in this photo). Each of these plants has 2 to 4 thin, wispy roots and do not appear to be developing further root structure.

For those wondering, the wavelength of these blue LED's is in the 460 to 470 nanometer range.

Photo Update: LED Lettuce @ 15 days

Shown here is the Tom Thumb and Bullet lettuce growing under blue LEDs. At 15 days I'd expect these plants to be a lot heartier under conventional lighting solutions.

There's a major problem here- the plants are 'reaching' which is a sure indication that they are not receiving the light that they need. The leaves are pointing upwards instead of outwards, which is bad. During the 'day' cycle, the leaves should be organized outwards and collecting light. In the 'night' cycle it is normal for the leaves to put upwards until the next day cycle begins.

Hopefully the problem is that the pure blue light is not providing everything that the plants need. If the problem is the quantity of light, changing the color will not help.

The good news is, my red & blue mixed LED panels have arrived so now I can start an identical crop under red and blue light for comparison. I wanted to run the tests side-by-side but a shortage of supply meant I had to wait an extra 2 weeks for my red and blue panels to arrive.

Today I'll get the red/blue setup built so that we can see if we can grow healthy lettuce under LEDs.

Photo Update: Cheapskate Lettuce @ 27 days

Here's my crop of Bullet romaine lettuce growing in a cheapskate deep-water culture system under a hydrofarm 125 watt compact fluorescent light. As you can see, things are going wonderfully for these guys.

The only problem is that I waited a bit too long to raise the light and the tips of some of the plants got burned slightly. When you grow under fluorescent lighting you have to keep the light as close to the plants as possible and raise the light as the plants grow.

These guys are ready for eating in about 10 more days. They normally grow for 50 days but we're going to take what's available around 40 days. I planted these guys too close to one another (I didn't realize how large they get!) and they won't be able to grow to full potential anyway.

Photo Update: Butternut Squash

Here's a photo of my poor burdened Butternut Squash. This guy has been through a lot as I've learned a bit more about how to take care of this type of plant. I had to do three major things to improve his quality of life:

-Drop the HID lighting from 600 watts to 400 watts

-Reduce the nitrogen level in the nutrient solution

-Run very frequent watering cycles (15 minutes on/15 minutes off)

All of these changes have this guy on the road to recovery but right now he has a lot of crispy leaves that need to be removed as soon as some healthy new growth appears. You can see several squashes on the plant but this is the second time it has tried to set fruit. The entire first round of fruits died on the vine. Hopefully we have better luck with this next round.

Photo Update: LED Lettuce @ 4 days

Here's a photo of the LEDduce that I'm growing. Get it? Lettuce under LED lighting. Ho ho!

Most all of the seeds have sprouted. It's interesting to note that the plants appear black under this blue light. That's because all of the blue light is being absorbed by the plant. Only green/yellow colored light would reflect off, giving the plants their green appearance, but I'm not providing any light of that color.

Just because the blue light is being absorbed doesn't necessarily mean that it is penetrating or that the plant is getting any photosynthetic benefit from the light. It's difficult to tell with seedlings because these are still operating on energy stored in the seed itself. Once more leaves appear we'll be able to make a better judgement about health and growth rates.