You have probably noticed that for each completed Puzzle level, you can order a Supply box. You can store up to three at any time and your current Supply boxes can be previewed under this icon (on the right side of the Home Garden):
There's a few kinds of the Garden Supply boxes; the longer it takes to order the box, the more valuable its contents and the higher chance for the box to contain Precious Gems:
Useful Supplies - 3 hours
Essential Supplies - 6 hours
Luxury Supplies - 8 hours
Handy Supplies - 10 hours
Deluxe Supplies - 12 hours
Opulent Supplies - 24 hours
If you're in rush or if you need a free slot in your Garden Supplies inventory, you can speed up the opening process using Gems.
Gems can also be used if you don't have free space in your Supplies inventory - you will be given an option to purchase the Supply Box at the end of each puzzle level.