We picked up a couple 14.9" square plastic garden planters from Home Depot and ended up creating some wood planter boxes from pallet wood for them to sit in. 

I didn't add up the cost of these boxes, because we had most of the wood and only needed a few pieces, but I'd say they were definitely less than $10 a box. 

We altered our dimensions to fit our HD planters so they would slip in for a snug fit and made the legs flush with the top of our sides. We build a simple frame for the top, which allowed the lip of our HD planters to sit firmly on top. 

Something I didn't do, but wish I did: fill in the cracks with wood filler.  There were a couple places that really could have used it, but I was in a rush and decided to skip it.  They turned out great, but could have been even better had I taken an extra 30 minutes.  On an off weekend, we are going to use wood filler in the seams, sand them down, and do a second coat of white paint. 

Can't wait to plant these with some mums for Fall! :)

Built from Plan(s)
Estimated Cost
$20 total for 2 boxes.
Estimated Time Investment
Day Project (6-9 Hours)
Finish Used
White Semi-Gloss outdoor paint
Recommended Skill Level