For the past couple of months WizKid has been working on a science project for his end of the year final. In Connections Academy these are called “portfolio” assignments and generally come with a rather hefty grade value attached. This particular assignment is worth a whopping 42% of his over all grade.
Being Mr. Little Grow Green who wants to save the ecosystems of the world, end poverty, eliminate pollution, waste and over consumption and do away with false foods (yes mom has taught him well), he chose a basic project of hydroponic mediums vs soil for plant growth.
The concept was simple; take three identical plants (basil) and plant each in a different growth medium.
One in plain potting soil.
One in gravel and sand.
One in nutrient rich water.
Over the space of two months record if any had a better growth rate than the others and if there were any noticeable advantages or disadvantages between the three.
To be honest the results were nearly what we expected and not overly surprising.
At first the basil in sand struggled and had to be watered every day. I think the gravel to sand ratio was too high, favoring the gravel, and the sand couldn’t hold enough of the water. A nylon rope was threaded through the hole in the bottom of the pot to act as a wick to draw moisture unto the roots.
It was very touch and go for several weeks but that little guy held in. Then one day it just started growing really well. Wiz thinks the roots finally grew enough to absorb the water it needed.
The soil pot did great of course as soil plants do. The only annoying issue, and one of the reasons we want to have all the plants in the house hydroponic, is soil becomes it’s own ecosystem and a breeding ground for pests. Little tiny flies especially that never seem to go away.
Th water plant did good for a few weeks but it started growing algae and it was very difficult to control. Sad to say it finally succumbed to the greater power. Such a tragic day when herbs die.
We had a moment if silence in the kitchen for our lost comrade and made basil baguettes in its honor. (with the healthy basil of course)
Over all I preferred the sand medium of the three and I would like to employ this method again. I do think I will mix a good portion of perlite or vermiculite in with the sand to give it that extra water retention power.
The benefit of this is it’s virtually a pest free medium. The disadvantage is the pots are far heavier and if you decide to plant something say like a tree, you’ll need a dolly truck to move it.
WizKid is nearly finished with his Power Point and I have no doubt he will get a perfect grade.
As for mom here, I couldn’t be prouder.
Doesn’t hurt I got two healthy basil plants out of the deal as well.
A girls gotta be practical right?
Want to try your own sand plant? Here’s a basic instruction to get you started with the modifications I will use next time. I’ll add more photos to the post when I do another one of these.
Note: these instructions are based on an 8 inch pot, adjust all sizes, weights amounts etc accordingly based on the size of pot you use.
1 8 inch plant pot with a drain hole and water dish
1 plant of your choice; I prefer herbs or edible flowers..
Enough fine play sand or decorative sand (found in the flower arrangement section of Walmart or craft store) to fill the pot 3/5 full
1/5 pot worth of aquarium or small pebble decorative gravel
1 bag perlite potting mix (the bubbly white stuff you see in plant soil)
6 inches nylon, cotton or other water retention rope, 1/2 inch minimum
3 or 4 square blocks of wood or other flat solid material that are 1 inch wide by 1/4 to 1/2 inches high based. PVC ring fittings are also ideal. They come in all sizes and are rot proof and can ensure a perfectly even base.
In a sturdy bucket mix 4 parts sand to 1 part gravel to 2 parts perlite.
Gently gently clean all dirt and soil from plant roots.
Unwind of carefully fray both ends of the rope. Then In plant pot, thread the rope through the hole leaving 2 inches dangling outside the bottom of the pot.
Holding the rope in the center of the pot add about one inch of the sand mixture to hold the rope firmly in place. You may want to place the pot on a rag or towel to prevent the sand from draining out of the hole.
Here’s the tricky part; dangle the plant in the center of the pot letting the roots pool just slightly on the layer of sand. with one hand hold the rope and plant together being sure the rope and roots are closely entwined or touching. With the other hand add a 1/2 to 1 inch layer of perlite on top of the first sand mixture.
Keeping the plant centered, gently add sand mixture to the pot up to one inch from the top (this will vary depending on the size of your pot, use your judgement).
Place the wood blocks evenly spaced in the water dish. These will become a support for the plant to rest on giving space for the rope to lie unobstructed at the bottom of the plate.
Carefully place the plant on top of the blocks, it’s heavy so make sure you know where you’re going to put this baby ahead of time.
Feed the plant with nutrient rich solution every day at first to soak the sand and perlite giving the roots time to adapt and suck up enough water.
Water as needed.
NOTE: if you find the plant is not absorbing enough water from the plate you can remove the blocks and place the plant directly in the dish. Be sure to coil the exposed rope in the center so it is not pinched or the plant unstable.
Did you try this project? Would love to hear from you.