Do I need grow lights? Update – Week 1

Week 1 Kratky Lettuce Compared

Previously

On the 17th July 2019 I planted some Deer Tongue Lettuce into our Aerogarden Bounty. My goal was to use the Aerogarden as a seedling starter to then transplant the lettuce sprouts into mason jars to test the Kratky hydroponics methods. Instead of using the traditional Aerogarden pods, we used Jiffy 36mm peat pellets inside the old aerogarden plastic cups.

On the 21st I painted some old unused mason jars with simple black gesso (two coats) to block out any light. I used some old yoghurt containers that just happened to fit perfectly on the mason jar. Using scissors, I simply cut some holes in the bottom.

I transferred the Jiffy peat pellet into the yoghurt container, and then propped it up with clay pebbles. The pebbles help block out any extra light out from reaching the bottom of the yoghurt container and leaking in to the nutrient rich water, as well as to help provide stability to the peat plug. The nutrients we used were from General Hydroponics.

To test the growing factors in each of my primary growing rooms, I placed one lettuce in my kitchen, one in the laundry, and one in the pantry.

1 Week Update

So how has the little lettuce been faring this last week? Already there is significant differences between each plant!

From left to right: pantry (next to AeroGarden), laundry, kitchen.

The first thing of note is that they have all survived! I was quite worried at least one would die during transplant. They have all grown, some more than others. All the peat moss plugs are still damp, meaning that each plant is still getting somewhat equal amounts of nutrients.

Left: Pantry

The lettuce from the pantry has clearly grown the most. It’s over 2x the size! We purposely put this plant beside an active Aerogarden as we figured we could capture spilled light from the Aerogarden rather than purchase grow lamps, after all the lettuce tubs can fit on the same shelf. This definitely gave an unfair advantage to the other two plants, but also allowed us to test how the Kratky method would compare grow light vs no-grow light.

This plants leaves are long and thin. Comparing with the Aerogarden, those lettuce leaves are slightly shorter but much wider. I currently don’t know why lettuce leaves will be thin or thick at the same age.

Finally, I should note that only one small root has emerged from the holes in the yoghurt container. At the moment its “just” peaking out, so not a strong root yet. This is the only plant that has shown any sign of roots beyond the yoghurt container.

It also seems that now the plants are bigger, there seems to be three seeds that have successfully grown in this one plug.

Contrasted with the actual AeroGarden model which leaves are much wider at the same length.

Laundry & Kitchen

These two sprouts are very similar. The lettuce from the laundry seems to be ever so slightly longer. The leaves are also about the same width, despite the picture above making the lettuce from the kitchen appear thicker (camera angle).

The leaves on the lettuce from the laundry seem more droopy, whereas the kitchen leaves are pointing straight upwards more. I am currently unsure what could cause this; more research will be done and we shall see how they perform over the next few weeks.

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