Last week I had, what I originally thought was, a brilliant idea. I recycled/upcycled/repurposed empty water bottles to be a self-watering/drip irrigation system for my avocado trees. To say this watering hack it didn’t exactly work would be fair, but it was a learning opportunity, which led to a pleasant discovery.
Let’s back up and I’ll tell you the full story from the beginning…
My Avocado Trees
In 2020 I Tried sprouting avocado pits to grow my own trees. The first two are affectionately named “Guaco” and “Mole” (as in guacamole).
I’m going to be very honest here and confess that sprouting avocado pits became a little bit of an obsession…At one point I had fourteen, I now have eleven healthy ones, and poor Rita (Margarita) is on life support after not tolerating the Texas summer heat well. The other losses were at the hands of the murderous and thieving squirrels in my backyard.
The heat in Texas arrived a little earlier than usual with it’s full there-must-be-a-magnifying-glass-between-Texas-and-the-sun force. As my avocado trees are still fairly small they are in pots. This makes water easy and tricky. It is easy to water the pots each morning, but the water runs right trough and pours out on the ground/ The soil does not retain much moisture, and what it does retain is subject to evaporation throughout the heat of the day.
This conundrum led me to attempting my own DIY self-watering system.
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DIY Drip Fail
The idea behind this “hack” was the blown glass globe that I got from my grandma that is stuck in my Croton plant in my bedroom. We’ve probably all seen these things on infomercials or on the “As Seen On TV” aisles at stores.
The science behind them is that you fill the globe with water, then stick the straw-like part into the soil of your plants. It releases the water into the soil as needed to maintain a state of equilibrium between the water in the soil and that in the globe – otherwise the water would just run out of the bottle and drench the soil.
The drawback to using these in my avocado pots is that they are a bit pricey, and needing a dozen made that cost prohibitive for me.
Don’t get me wrong, they are effective and beautiful, and I love the one I have for my indoor plant, but for an orchard of avocados I needed something more financially reasonable.
I decided to make my own with that same concept, but with a drip component to allow a slow and constant source of water to help these plants through the heat of the summer…
To start I took some wooden skewers and duct taped them to the top of the bottle (creating a stake system to hold the bottle upside down in the soil of the pot).
I then removed the bottle’s lid and poked a hole in it with an icepick. After that I shoved a Q-tip through the hole in the lid, then filled the bottle with water and screwed the lid back on. I then turned it upside down and gently pushed the skewers into the soil on the outer edge of the pot. Then I confirmed the water was traveling from the bottle down the Q-Tip and dripping into the pot.
The concept was very much like that of an IV drip in the hospital.
I proceeded to make the rest and placed them in the post of the avocados.
The next day, I noticed a bottle had fallen off its skewers, so I went to fix it… That is when I noticed all the Q-Tips were bone dry – despite the bottles all still having the vast majority of the water they started out with.
The diagnosis/conclusion I have come to is that they cotton end and rolled paper middle of the Q-Tip ended up absorbing as much water as it could, then essentially created a clot at the hole in the lid. This led to the flow of water (and dripping) to stop. Or…the Texas summer heat dried the water on the Q-Tip before it could collect enough for another drip. Either way, it was a rare DIY FAIL for me. Luckily, I did not have much invested in this experiment.
My Solution
After assessing the situation, I decided to look for alternatives on the internet. I eventually discovered a compromise between the original pricey globe and the DIY disaster…
These things use the bottles I was already using, then the spike gets poked into the dirt. When inverted, the water from the bottle pours into the little cup-like section where it maintains the equilibrium and drips (at the rate you want – determined by how tightly you screw on the small regulator nozzle. They maintain a constant dripping speed until the bottle is empty. Then you simply refill them.
The small page of instructions also show you the formula to calculate the number of days you can get out of one bottle of water, when used inside, depending on the drip rate you have set.
Days = ML x S /4320
Meaning, the number of days of constant dripping in your plant is the number of milliliters of water in the bottle (times) the number of seconds between drips, all divided by 4320.
For example, if I have 1,000 milliliters in my water bottle, and I set the regulator valve to one drip of water every 43 seconds, I would multiply 1,000 by 43. That would give me 43,000, which I would divide by 4320 for a total of 9.95 days of watering from one bottle. That math comes in handy if you are wanting to use these to water your indoor plants while away from the house/on vacation.
When using them outside, if you live in a hot and sunny place like Texas, you will not get a full 10 days out of one 1,000 ML bottle dripping once every 43 seconds as calculated above, because of this little thig called evaporation. This means you may need to refill your bottles more often, but the concept of drip irrigation still holds.
These are a fraction the cost of fancy blown glass option. They are reusable and I am still able to reduce/reuse/upcycle my old water bottles.
Unless you want something pretty, these are a great option for creating a self-watering system in your garden or indoor plants.