That's My Letter: "D" is for DIY House Number Plaque -- not plants, but outdoor related. ;-)
Paint Stick and Scrap wood make a cheap and easy way to add some curb appeal to your front door! This is such a good idea and could be customized to any color scheme to match your house!
That planter box house number thingy stuck in the ground.
DIY House Number Plaque made from paint stir sticks. - 4 Men 1 Lady
Design My House Number by Plastic Republic - Range of products from Individual house numbers, plaques and signs.
DIY House Number Plaque using a thrifted platter, glue and numbers
How about this for a really unusual present, especially for someone who has just moved house. Nail house numbers Tesco
DIY house number plaque, oval house number
DIY for address plaque with glow-in-the-dark (at least for a little while) numbers and a secret key compartment - by Matt2 Silver [Instructables]
Custom Vertical House Address Number Sign Plaque Personalized HP Wood