I garden like a spastic four year old. I plant a bunch of stuff, get all excited about it and then wander off and find something shiny. My poor plants die of dehydration and neglect and I throw a temper tantrum when I have no mint for my tea and proceed to plant a whole new batch of victims. I have spent the past several years attempting to ameliorate my planticidal tendencies with varying success and have finally achieved a solution I find acceptable. I started with a basic homemade earthbox, redesigned it to my own liking and I now spend my summers happily drowning in tomatoes and eggplants. I made small earthboxes out of smaller tubs for my summer herb garden, and while they worked great, they were too unwieldy to bring inside for winter eating. Also, I drink way too much soda. Seeking to kill two birds with one stone, I constructed these little self watering pots to simultaneously house my abused flora and justify my excessive carbonated beverage intake. They are sturdy and low maintenance; and, trust me, if my plants can survive in them, a normal non-serial-plant-murdering person's plants should thrive.

Step 1: First, You'll Need Supplies.

You'll need the following items procured by whatever nefarious means you deem necessary. Or don't, if you've got sufficient stuff lying around the house why are you going out and buying new junk? Personally, I spend an inordinate amount of time haunting the aisles of the dollar store and found most of the non-recycled items I needed there, the only notable exception being the potting soil.

To make the pots out of:

Empty plastic bottle. I'm using 2 liter soda bottles. Use what makes you happy.
Tulle or some other cheap mesh that won't rust or dissolve (plastic is best). Those little plastic mesh circles pictured above come 15 to a pack at the dollar store and work better than anything else I've tried. They don't rot like fabric and they don't rust like metal.
Zip ties, fishing line or some other means of securing the mesh.
Tape. Clear plastic packing tape is ideal, it melts, is see through, and works. Duct tape also works but isn't see through. There's very little stress on the tape, so fancy waterproof NASA tape isn't necessary.

To beat the pots into submission:

Scissors, a dremel or a knife sufficient to cut the plastic, pointy is good, don't stab yourself. I tend to use a scalpel or xacto knife to remove the label and start the cut then finish with the scissors. If I'm making a lot of pots, I'll use a dremel with a cut off blade.
Optional: I use my soldering iron with a pointed tip to make the holes, it's faster and easier than drilling them, safer than stabbing them, and it doesn't tear at the plastic. Plus, the melty hole seems stronger than a drilled or punched one. Just don't breathe in.

To fill the pots:

Potting mix. If you make your own, nifty, you probably kill fewer plants than me. If you are buying your soil, don't buy the stuff labeled garden soil, make sure it's potting soil.
Water.
Sand. (Sort of optional.)
Some form of non-deceased plant life. I'm good with herbs. Culinary herbs, you hippie.
Optional: aspirin, seed starting mix, rooting hormone, your preferred method of avoiding plantis-mortis.

Step 2: Clean the Bottles.

Rinse out your bottles with hot water, and if you deem the previous contents sufficiently icky, with soap or bleach. I just use hot water on soda bottles and haven't had a problem. If you mind water dripping on your pants while you work, either let the soda bottles dry completely or work over a towel. Remove any labels or stickers that will get in the way. Remove any labels or stickers that won't get in the way unless you like them.

Step 3: Cut the Bottles.

Cut the bottles horizontally at the halfway or 2/3 point. The top half should be the larger half, the larger the top half is, the more soil your plants will get. The bottom half just has to be big enough to hold the top. See the notes on the picture above for a (hopefully) less confusing explanation.

Step 4: Attach the Mesh.

Take your mesh (tulle) and using a zip tie (easy) or fishing line (complicated, requires more hands than I have) fix the mesh over the mouth of the bottle. Easiest method is to make your loop, place the mesh on top of the mouth and then slide the loop down and pull tight. Make sure your tie is tight, you don't want the mesh running away. Trim any excess but DO NOT throw away the excess mesh, you need it.

Step 5: Poke.

Poke some holes in the bottle around the mouth. I use the soldering iron for this. Don't make the holes huge, and you only need a few.

Step 6: Insert.

Insert the top half of the bottle into the bottom half of the bottle, with the mouth towards the bottom. The mouth of the bottle should be almost touching the bottom, I leave about 4 mm (1/8 inch) clearance between the mouth of the bottle and the bottom. When the two parts are positioned to your liking, use the tape to secure it in place. Using the soldering iron, a drill or knife, add an air hole close to where the curve of the top half of the bottle meets the wall of the bottom half. Add a slightly larger water intake hole below the air intake hole. In the image above, the air hole is close to the water intake. I usually put these holes on opposite sides of the bottle. I usually add two holes above the curve of the top half, on either side, because I have some half brained thought about oxygenating plants that you should probably ignore.

This is important: remember that leftover mesh from step 5? Stuff that loosely into the mouth of the bottle before going any further. If you lost your mesh or didn't have any left over, go find some. This ensures that the water works right. If you don't do this, some of your plants will refuse to drink. I know. They die.

Step 7: Add Dirt. and Stuff.

Fill your nifty new thingy loosely with dirt. Don't pack it down. Pour water over all the dirt, this will level it out and compress it. Pour in water, moving the water source so all the dirt is soaked, until the dirt is wet through and the bottom half of the pot is full to the water intake hole. Do this outside or in the sink as you will most likely get overflow.

If I'm planning to transplant a seedling or a cutting, I usually use filtered tap water with aspirin added for this initial watering because I read somewhere that aspirin reduces transplant shock. I don't know if it actually works, but it hasn't killed anything yet and it makes me feel better about myself. I fill a bottle with water, add half an aspirin tablet (there is nothing scientific about this dosage, I made it up) and put the other half of the aspirin in a little baggie and attach it to the bottle with a rubber band for the next time. I use this aspirin water on my plants when they look sad and add it to flowers in vases. It seems to make the plants happy, or maybe it makes me happy and I'm just projecting.

If I'm planning to start the plants from seed in the pot, I brew a weak pot of chamomile tea and add the aspirin to the tea. I heard from somebody I don't remember, or read somewhere, or something, that chamomile tea will keep seeds from going moldy before they sprout. Like all random trivia that enters my brain, I decided this was gospel and now water all my seeds with chamomile tea.

Step 8: Add Plants: Seedlings or Cuttings

I love cuttings. The idea of cutting off a limb and growing a whole new pers...er plant is awesome. And it's disturbingly easy. Like the plants want to survive and take over the the world or something.

To transplant seedlings into your pots, add some potting soil to pot, then put in the seedling, fill in around the edges with dirt and add aspirinated water. Add soil as necessary to fill in the gaps. Leave about 4 cm/1.5 inches at the top. Don't pack things down, let the water settle the soil without crushing your little baby roots. You can always add more soil later.

To start cuttings: take a cutting from the plant you want, preferably a stem without a flower/bud. Strip off all but the top few leaves. Dip in rooting hormone (optional). Fill pot with soil and soak with aspiriny water as described in the previous step. Poke a hole (or holes) in your soil and stick your stem in the soil. Add more water to redistribute the soil around the stems. Stems should be firmly in the soil, but don't crush them. A note about rooting hormone: like aspirin and chamomile tea, I don't know if it works, I've started cuttings successfully without it, but I figure it hedges my bets and it seems to work for me. I bought the bottle in the pictures years ago and it lasts forever. If you don't already have any, try without it and if you have problems, then try with it. I have managed to start plants using the herbs you buy in the little plastic thingies in the stores by trimming the bottom 2 cm/.75 inch and using rooting hormone.

Step 9: Add Plants: Seeds

To start plants from seed, add the soil as described previously. As stated previously, I use chamomile tea with aspirin instead of water for the first watering. Once the soil is thoroughly soaked, tamp it down lightly with the bottom of a cup or other tamping object to make it flat. Then add a thin layer (6 mm/.25 in) of seed starting mix. I find starting the seeds in just the potting soil has a lower germination rate, I'm guessing because the larger chunks in regular potting soil just don't provide purchase/moisture to the seeds. Since it tends to be very light and float on top of the water instead of soaking it up, it is often easier to soak the mix before spreading it on the pot instead of adding it dry and watering it. Sprinkle the seeds on the dirt according to the instructions, putting more dirt on top if the instructions on the little packet say so. Or, if you are me, ignore the packet and do whatever you want to anyway, consequences be damned. Dump those seeds willy nilly and complain bitterly if nothing grows.

Step 10: SAND and Fungus Flies

There are these horrid, awful, nasty little gnat like things called fungus flies. They love wet soil. They also love to fly up your nose. The will infest your beautiful little potted babies and murder them all. Especially since these pots stay wet. They are your enemy. You must destroy the enemy. The enemy is everywhere.

Adding a layer of sand to the top of your pots seems to work. I use pool filter sand because it's coarse and it was the only alternative to playground sand when I was looking for a way to keep the hellspawn out of my precious pots. If you see little dots on the leaves of your plants clean them off with a mild dish soap/water solution. If you know of more, better ways to get rid of these monsters, please, do tell. The usual solution with houseplants is to avoid keeping the soil too wet, but that's not going to work here.

For transplants/seedlings I add the sand as soon as I plant them. For seeds, I add the sand once the plants are firmly established. I'm of the delusion that the sand will do something to the seeds if I add it too soon, but I don't know what.

Step 11: Water Your Plants.

I tried a ludicrous number of absurd means to water these pots. I installed straws and watered with syringes, used tiny funnels and squirted water everywhere but in the reservoir where it was supposed to go. I'm a moron. Watering is easy.

Obtain clean vessel wider around and at least as tall as your pots. Fill vessel with clean water. Shove pot in water. Wander off. Come back, take pot out of vessel and leave in sink/outside for a few minutes because there will be some overflow. Put pot back in its home. Water next pot.

I live in the desert, so humidity is low. I refill my pots with water about every ten days, sooner if the water level gets too low. Depending on a multitude of factors, this rate will obviously vary. My understanding of botany being minimal, I'm not sure if I'm correct about this or not, but here's my experience: don't wait for the soil to dry out like you would with a regular potted plant. Water based on the amount in the reservoir, never letting it go below the mouth of the top half. Even though the soil is always wet, I've not had problems with mold.

You will likely grow lovely, bright green algae in the bottom half of your pots. Society has trained me to believe algae good, so I leave it alone. When the plants get too big for the pots (rootbound), I usually just take cuttings and start new plants in new pots and do absolutely nothing to aid or transplant the poor overgrown things. They keep living on me, often until the reservoirs are so full of roots snaking through the water they look like teeny tiny mangrove forests. I'll let you know if one dies of old age.

Step 12: The End. I Talk Too Much.

I'm tired of taking pictures now, and the dogs are threatening mutiny if they don't get some attention, so here are a few random pictures of plants in my pots, on the kitchen windowsill and in my tiny 4 ft x 4 ft greenhouse. I have pots on most of the windows in the house and in the greenhouse. Ages vary, and I use a heavy hand when cooking with herbs, so these are constantly, brutally denuded. I have one pot with a chocolate mint in it that has a large water reservoir and a tiny soil area (the bottle was cut just where the curve straightens out.) It has survived over a year now and the water reservoir has a sheet of weird algae-mold-alien-brain-something-IDon'tKnow growing in its middle (well below the water line, mold on top I would understand), but the mint just grows happy as can be. I'm not sure how well it shows in the pictures, but I did experiment with several heights/soil to water reservoir ratios. If you don't like my way, do it your way, I swear I won't notice.