Here is an idea for a cheap and easy way to make a self-watering planter from a milk carton. Great for school projects, home gardening projects etc.
Step 1: Cutting the Carton
After cleaning the milk carton you cut it about two thirds of the way from the bottom.
Step 2: Cut a Wick
Cut a wick from a piece of cotton cloth. Any old rag will do.
Step 3: Insert Wick
Insert the wick into the carton top and close it. A bit is to be inside, but the part on the outside has to be long enough to reach the bottom of the carton. It is easy to adjust this later.
Step 4: Insert Reversed Top Part Into Bottom Part
The top part with the wick goes into the bottom part neatly like this.
Step 5: Time for Planting!
In this example I am planting tomato seeds. Seeds from a tomato has dried on a piece of paper towel. I cut out four to be sure to have at least one healthy plant. Add potting mixture up to about 2.5 cm (1 inch) from the top. put in seeds and add more mixture until just covering the seeds.
Step 6: Add Water
Fill the water reservoir and pour a bit from the top too so that the soil, seeds and wick are wet. The wick will bring up more water when needed.
Step 7: Top Cover
Add some small pebbles to slow the evaporation of water from the surface.
Now you just have to wait until your plant comes up. Keep an eye on the water level and add fertilizer if needed. Tomato plants grow quite big, so they have to be re-planted into bigger pots - mine should have been a bit earlier, they look a bit sad.
I am sure you will do a better job - good luck!