You're out in the garden and you forgot to bring your trowel with you. So you stop what you're doing and dash back to the garage or toolshed to find it.
Here's a better solution: Keep your hand tools in the garden where you need them, but store them in a converted mailbox.
The wooden mailbox pictured here, purchased at a nursery, is mounted atop a 6-foot-tall 4-by-4 redwood post and secured with a 3-inch-long lag screw.
Tucked in a perennial bed within easy reach of a path, it keeps tools close by when spent blooms need clipping. (Another good place to put a tool hideaway is just outside the back door.)
Drill a hole in the top center of the post and also in the bottom center of the mailbox of your choice. Set the mailbox on the post and screw it in place.
Make it movable
Anchoring the post in sand (you'll need a 10-pound bag) allows you to move it easily at season's end.
Dig a hole 2 feet deep and 6 to 8 inches wide, pour a 6-inch layer of sand into the hole, position the post in the hole, then fill in around it with sand and tamp it down firmly.
Or for a more permanent storage box, set the post in concrete.