There have been some posts on recycling used CD spindles lately. By the miracle of physics, when turned upside down a CD spindle becomes a water-tight container! I like to use mine as bases for my plants. These plants grow very quickly when they have very moist soil, so I fill these up every few days.
These plants are both grown from seeds I got from the fruit. The one on the left is a Grapefruit, and the one on the right is Avocado. The Grapefruit is actually 1.5 years old and grows in spurts. At this rate, it will only be 20 years until I can eat a Grapefruit from the tree.