Don't Throw It Away! Use That Plastic Bottle in the Garden!
Here's a link to another post on gw, showing how to poke holes in a plastic bottle, sink it into the ground, & use it to 'seep' water to tomato plants.
You can use the technique on other plants of course...
What other uses have you found for these bottles?
Here is a link that might be useful: Using Plastic Bottles to Water Tomato Plants Slowly