All you need to make your own growing system a glass aquarium and mesh lid, an aquarium light, a full spectrum light, pebbles, charcoal, soil, plastic wrap, tape and seeds. To take the project from low-tech to high-tech, you'll also need Parrot Flower Power and a LittleBits Smart Home Kit.
Plants that live in a terrarium environment need more than just potting soil to grow. A layer of pebbles, charcoal chips and potting soil allows the soil to stay moist, but not too wet, allowing extra moisture can drain away from the plant's roots. To get the growing environment just right, layer 1 inch (2.54 centimeters) of small pebbles along the bottom of the aquarium. Next, put a 1-inch (2.54 cm) layer of charcoal chips over the pebbles. Finally, add 3 inches (7.62 cm) of potting soil.
At this point, you can either plant seeds in the soil or you can add live plants. When you're done, spray the soil with water until it's moist.
I've found that this little growing system is perfect for re-growing vegetables I've already bought at the store. For example, I cut the bottom off of a cabbage and a celery stalk and planted them in my terrarium. They have rooted and grown new leaves that I can use in salads.
Stake the Parrot Flower Power module in the soil and sync it with the Parrot Flower Power app. The app will send you alerts when your plants need water so you'll never need to guess. If you are planting more than one type of plant, you may need more than one module, since it can only monitor one type of plant per module.
You won't need to water your plants very often if you make sure that the moisture can't escape your growing system. Tape a layer of plastic wrap to the inside of the mesh lid with clear packing tape and place it on the aquarium. The water that escapes from the soil will drip back down onto the plants because it won't be able to escape the glass box.
Next, you will want to add a light to your growing system. All you need is an aquarium light fixture that will fit the tank as well as the right bulb. For plants, you'll need a full-spectrum daylight bulb. These are usually sold in pet shops, so you can purchase the tank, light unit and bulb in one shopping trip. Put the bulb into the light unit and set it on top of the mesh lid.
You could stop there, but I went a step further and made it so I could control the growing light with my phone. To do this, I used a LittleBits Smart Home Kit and these instructions for setting up a wireless lighting control. I like this set-up because I keep my growing system near a window and leave the light off on sunny days. On cloudy days, I can turn on the growing light no matter where I am.
Purchasing this kit makes your growing system more expensive by quite a bit, but if you're making a large growing system using a 50- to 100-gallon (189- to 379-liter) aquarium, it would be worth it when you compare the expense to prefabricated growing systems of similar size.