A few weeks ago the girls and I did a project that I've been enjoying every day since. We repurposed 2 liter bottles and turned them into self-watering planters for starting our tomatoes and cucumbers indoors. They've been sitting on the window sill near my desk and I've been watching them grow every day. It's been the perfect antidote for the bummer weather we've been having here in Seattle.
I've tried starting seeds indoors several different ways over the years. So far this is my favorite method because the soil is always exactly the right moisture level and it's very easy to see with the naked eye when it's time to add water to the planter. There's no guesswork involved and the plants seem to love it.
Here's how we made them:
You need 2 liter bottles, potting soil, seeds, thick string or yarn (either cotton or poly seems to work), a Phillips screwdriver, hammer, and a sharp blade to cut the bottle.
Cut the bottle in half.
Use a Phillips screwdriver and a hammer to punch a hole in the center of the bottle cap.
Cut a length of yarn/string about 1'-1.5' long, double it over and tie a loop on one end.
Thread the yarn/string through the hole in the bottle cap so that the knot is on the inside of the cap. This will act as a wick, drawing water up from the basin below and into the soil. The plant will take only what it needs, so the soil moisture will be perfectly regulated.
Put the cap back on the bottle top and nest the top of the bottle in the base. As the plants grow and use up the water, you can just lift off the top to add more to the base instead of pouring it over the soil. As the soil dries, water will be sucked up through the string into the pot.
Label your bottle so that you remember what you planted. :-)
Add potting soil and seeds...
You need to water the soil from the top the first time in order to make sure that it is uniformly wet and that the string also is wet. Otherwise the surface tension of the water will prevent the whole thing from working correctly.
A note to all readers:
I've had lots of great comments and questions about this post, many of which I'm not able to answer myself because I just don't have the broad range of knowledge about plants that is necessary. If you do have that knowledge, please feel free to jump on board the comments string with your input. It would be greatly appreciated!