How to Make a Self Watering Pot to Keep Plants Watered

Self watering pots use a system called sub-irrigation. Sub-irrigation relies on your plant and the soil's natural ability to wick water upward as needed. There are benefits to this system. First, it allows your plant to "decide" how much water it needs without adding your own guesswork into the equation. Secondly, it encourages your plant's roots to grow downward, making them better established. Finally, it doesn't cause the same soil displacement and washing away of nutrients that top watering can. Sub-irrigation planters are easy to make. This project uses recycled pop (soft drink) bottles.

Things You'll Need

• Empty 2-liter pop bottle with lid
• Utility knife
• Aluminum can
• Permanent marker
• Solderer (optional)
• Chopstick (optional)

Instructions

1. Fill the pop bottle with very hot tap water. Do not use boiling water because this shrinks the bottle. Let it sit for a minute or two while it melts the label adhesive. Remove the label adhesive and discard. Pour out the water. Replace the bottle cap.

2. Place the uncapped permanent marker horizontally on top of the can. Hold it steady with one hand while you bring the bottle to it with your other hand. Rotate the bottle against the marker tip until you've drawn a perfect line around the outside midway up the bottle.

3. Heat up the solderer. Use the pointed end of the solderer to make three to five small holes in the bottle's cap. If you do not have a solderer, use a craft or utility knife to poke holes, and insert a chop stick to widen and round out the holes. This also works with a pen.

4. Use the solderer to make a row of aeration holes at the shoulder of the bottle, just where it starts to curve in toward the cap. Make a second row below this to allow air to reach the roots. Make one small hole about an inch below the line you drew to help keep your pieces from sticking together.

5. Cut the bottle in half with the craft knife at the black line you drew. Use your craft knife again to smooth out any jagged edges you may have created while cutting.

6. Invert the top of the bottle so the cap is facing downward and place it inside the bottom half of the bottle. It should almost touch the bottom. If it doesn't, use the craft knife to trim off about an inch at the top of the bottom piece and try again until you have the right size.

7. Fill the container (top bottle half) with moist potting soil and your plant. Use only moist potting soil, as dry soil is less likely to start wicking water upwards.

8. Fill the reservoir (bottom bottle half) with water and watch as your plant absorbs only as much water as it needs.

References

• Self Watering Pop Bottle Instructions
• Make a Self Watering Planter from a Pop Bottle