Here's a pretty planter box I found online. That's what I'd like to build! 
How to build a planter box?
by
Ann
I'd like to know how to build a planter box to put out on my porch. I love flowers and I want to be able to display more of them in front of my house by building a planter box. What materials do I need and how do I go about building a planter box? I know there are tutorials online, but there are different ways to do this and I want to know what has actually worked for people. Can someone give me step by step instructions that you have used to make a planer box? Thank you!
A simple planter box made of 1 1/2 inch thick cedar boards would be a good choice. It's a hardy wood, perfect for a planter. The easiest way would be to determine the length and width of your box and then to simply cut the pieces to size and screw them together. If you wanted something a little more intricate, I find the Family Handyman has some great tutorials: https://www.familyhandyman.com/landscaping/12-diy-planter-boxes-you-can-make-in-a-day/view-all/
Be sure to provide adequate drainage -- and consider the weight .... wooden box + dirt + water + plants = ## .. be sure they are securely anchored or not at risk for falling on someone's toes!
masonry anchor bolts -- if attaching to brick .... or if on siding, be sure you find a king / queen board or a stud ... they make brackets .. https://www.youtube.com/watch?v=z6nUAffaL3s -- brick
https://www.youtube.com/watch?v=Ji6jkO79C6M -- Siding ... ( this is not vinyl, but the principle is the same )