This plant has not only been alive since 1960, it hasn't been watered since 1972 either. And I can't keep a cactus alive? 

It's a beautiful example of a closed but functional ecosystem, David Latimer has grown a garden sealed inside of a giant glass bottle that he has only opened once since he started growing it.

Latimer planted the garden on Easter Sunday in 1960. He placed some compost and a quarter pint of water into the 10-gallon glass jug you see and inserted a spiderwort sprout using wires. In 1972, he opened the garden again to add a bit of water. With that one exception, the garden has remained totally sealed – all it needs is plenty of sunlight!

What the heck? How in the world can this stay lush and beautiful and I can't even keep a tomato plant alive all Summer? The garden is a perfectly self-sufficient ecosystem. The bacteria in the compost break down the dead plants and break down the oxygen given off by the plants, turning it into the carbon dioxide that the plants need to survive. The bottle is like a mini Earth. It's quite primitive but clearly shows how we can eventually survive on other planets growing food contained in the amazingness of nature and all it's splendor.