I LOVE to make homemade pizzas! My favorite is a Margherita with fresh Basil. My efforts at making pizzas is always challenging when Summer is over and fresh Basil becomes scarce or expensive! I'm cheap!
Basil is an easy plant to grow in the summer but Basil thrives between 80-90 degrees Fahrenheit, need lots of root growth room, and MUST have at least 6 hours of sunlight-- or they will "bolt," bud/flower and perish shortly thereafter. Some enthusiasts try to keep up with plucking the buds relentlessly but, "Aint nobody got time for dat!"
With the LED technology and Arduino technology available to us today, creating a better environment for plant growth is easy.
Step 1: Things You Will Need
3. Hot glue gun (optional-- I used it because it was easy on low pressure water fittings ,but may not be useful for higher water pressure. Con: It looks rigged and "ghetto.")
4. Soldering Iron (optional)
5. Pliers with Wire Cutters
1. Two large, cheap, and clear plastic totes. -- Walmart $5 each
2. 6 to 12 small bolts and nuts to hold tubs together and optionally place hinges.
2. Masking Tape
3. Handles and/or hinges (optional)
4. A small ceramic heater with thermostat. I bought one for $10 at Walmart
5. LED Grow Light with timer-- https://www.amazon.com/GreenLaren-24-Hour-Mechani...
6. Arduino UNO
7. Hygrometer-- http://www.ebay.com/itm/Soil-Hygrometer-Humidity-...
9. 5mm LED (optional)
10. NPN transistor( I used a 2N3904 but a 2N2222 may be a little more resilient as it handles a wide array of variances -- The 2N2222 is a tough little bugger!)
11. Old, used washing machine water fill solenoid. ( This can be picked up from an appliance repair shop as these things go bad all the time. A standard washing machine uses two of these. Most of the time they are joined together -- hot and cold. One will go bad and the other is totally fine. I sawed the two apart and separated them. Most are 12v driven, but some are 120v AC. You want the 12v solenoids, if possible. Mine is rated at 3AMP but I put a 1.5 AMP power supply on one and it works great. )
12. 12-volt power supply
13. Fish tank tubing
Step 2: Create Your Tote Terrarium
I did it this way and because it was super inexpensive and I was able to use some old stuff.
I initially looked for a clear plastic trash can but couldn't find anything that was cheap. Because -I'M- cheap, I went to Walmart and bought two identical plastic tubs, less than $5 each. I discarded the lids and placed them top to top.
I wanted to be able to open the terrarium easily and be able to take plants in and out so I needed a large opening. I decided to cut the top tote lengthwise and hinge it on the bottom. I had the hinges lying around and a set of cabinet handles as well. I'm not sure what the cost is if bought new but I'm sure some tape and a knob of wood or something would work just as well.
CUTTING the plastic tote was simple but make sure you use a high RPM saw. Use a piece of masking tape and run it from one end of the tote to the other as a cutting line. If you use a jigsaw I or handsaw your results may vary as these plastic containers are made of brittle plastic that likes to split, crack, and shatter. I used a tablesaw and it cut very smoothly. Try to keep steer clear of cutting the corners or regions around the handles of the tote as these areas are designed to give the tote strength. If you DO get a crack, use a heat gun (careful with distorting the plastic), or press with an iron between two pieces of parchment paper to mend. Hopefully you won't have to go there. I used small bolts and nuts to bolt the two totes together.
After the tote was complete, I drilled a 1-1/4 inch hole in the back for the heater cord, and water supply tubing.
Step 3: Place the LED Light
I took the goose neck off of the light (required soldering. This is optional. My intention was to make the terrarium the least ghetto as possible.) I drilled a small hole in the top of the terrarium and dangled the light inside. I used wire ties as stress relief on the wire. Later, I decided to use a small piece of wire to direct the light--- Hmmm... Maybe I should have just used the goose neck?
Step 4: Place Your Ceramic Heater
Just put your ceramic heater in-- easy enough... but wait! Make sure you adjust the thermostat!
Something about putting a heater inside a plastic enclosed tub is wrong, right? I would suggest making sure your heater has enough clearance to circulate air well and plug your system into a GFCI outlet for safety.
There are planter heating pads available at nurseries that are waterproof and made for this type of application but as long as you're giving a modest amount of clearance, you should be good. The heater should be able to heat the small terrarium in a matter of a few seconds and will switch back off.
Step 5: Create Your Watering System
Your Basil plants need plenty of water when they are in their happiest 80-90 degree environment.
I used an Arduino to create this watering system. I soldered all of the components together and wire tied the wires for stress relief, but a breadboard would be just as good.
Here is the code for the Arduino. More than one hygrometer can be used but this code is just for a single solenoid. The jist of the code is to have the sensor turn on every eight hours and check for water. Important: The prongs on the sensors are easily corroded in soil if placed on a continuous charge so I have it switched off until needed. If watering is needed, the time needed for watering is deducted from the eight hours so the eight hour mark should be --at least a little more-- accurate.
For larger projects, I'm sure the 1/2 inch tubing would have been fine, but the stiffness of the tubing wouldn't allow me to place the end in the tubing into the plant easily. I wanted more flexibility, so I used fish tank tubing-- perfect!
Attach the relay-switch to the 12-volt supply of the flow solenoid.
I used a cheap tupperware container as the water reservoir on top of the terrarium. The solenoid is attached to the tupperware and the fishtank tubing is run to the plant.