My wife and I were renovating our living room, and looking for a way to add more plants to our home without taking up too much floor space, as well as have more light by our windows. We designed a hanging planter that gives light to the plant and to the room, and additionally has plenty of space for water so we can go on a holiday without worrying about watering the plants (or otherwise kill our plants, by forgetting to water them every week.)

Using this design you can grow plants anywhere you like in your home! Put a few over your work desk or dinner table, it doesn't need to be near a window. The plants won't even take up space on your table, and you get a bit of extra light too.

Step 1: Bowl

Get a stainless steel salad bowl. It's important that it is really stainless as this will be holding our water.
Make holes for rings to hang the bowl by. I found it easiest to punch the hole with an iron nail. I used four wires to hang the planter.
Add rings to the holes.

Step 2: Lights and Wires

Glue led strips inside the bowl. I'm using two strips with different light colors. The other one is used during daylight, and the other one gives a warmer color during evening time. I'm using an aquarium led timer that automates ramping up the lights smoothly every day, and dimming them for the evening.
Tie wires into the rings. Here we use 2.5mm2 gauge speaker wire. It's sturdy enough to hang the heavy plant and water, and additionally we get the 12v electricity to the led strip through it. Remember: Use a transformer, and not mains voltage - that could kill you.
Solder each of the wires to the led strips. To make the connection more secure I also hot glued the ends of the wires down so that moving the planter is less likely to dislodge the soldered joint. It's important that the knot tied at the rings, and not the solder joint, carries the weight of the planter.

Step 3: Self Watering Planter

To put the plant in I bought an off-the-shelf sub irrigating planter, sawed it to fit inside my salad bowl, and made a hole through the bottom. Then, using a soldering iron I welded the wicking part (the black cup in the middle) under the planter. You can take any old plastic container you might have that fits in your bowl, then weld on a plastic cup with small holes near the bottom that leads to the bottom of the bowl to wick in the water. I added a pipe for watering, but you can also top up the water from the edges of the bowl.

Step 4: Plant Your Plants

Thing's I've learned from using self watering containers.

A sub irrigating planter will keep your soil constantly wet. Not all plants like that. By chance I happened to select plants that seem to thrive in these planters: Spider plant, Polka dot plant, Chinese Money Plant, and some others I can't seem to name. If your plant dies in your sub irrigating planter, choose a plant that likes its soil wet.
There are special soil mixes available for sub irrigating planters. I've found that they still don't make the soil airy enough for some plant species. The type of soil might make a difference for some types of plants though.

Step 5: Final Thoughts

Before posting this I wanted to be sure the planters really do their job and keep the plants happy. By comparing these pictures you can see how much the plants grew in almost exactly a year. This growth took place in Central Finland, a country with a Northern climate, and very little natural light during the winter months. We've actually been quite surprised by how much the plants seem to like their pots, seeing as we're definitely not expert gardeners! :)

Thoughts on our plants and their care regimen:

We top the water about once a week, sometimes there's been even two weeks in between. It's very important not to put in too much water (or your plants might choke), the maximum amount to fill is just below the bottom of your soil reserve. That way there's plenty of air in contact with your water reserve, and the soil doesn't sit in the water.
I didn't add any fertilizers during the first year since the plants seemed to grow well enough without any. I think I might start adding some in their water every now and then to keep them happy, but they're really big enough already.
The chinese money plant likes to grow leaves right against the led strips. It's a dumb move, since the leaves touching the leds dry out and die soon. So don't go overboard with your lighting: Even though the steel bowl cools the leds down, they can get quite warm.

Thanks for taking an interest in our plant light project! Happy planting!

Best,
Ville - full time indie game developer (www.instantkingdom.com), part time crazy indoor gardener. :)