How to build your own outdoor flower boxes

This week our Jill of All Trades shows us the easiest way to build some basic flower boxes. 

The flower boxes on Jill's house had been up for years and were really starting to show their age. In fact, one of them gave out and actually fell off over the winter. It was definitely time for an upgrade, says Jill.

As is so often the case, materials really matter for a job like this. Jill chose 1x8 cedar for these flower boxes because cedar holds up much better over time out in the elements. To save money, she chose rough-sawn planks. That cut the cost of the lumber by about 75%! Since Jill didn't want the rough sawn look for her flower boxes, she just turned the rough side inward and let the smooth side show.

Jill also made a concession when it came to the trim piece on the top. She used 1x2 pine for that because it won't be touching the earth like the cedar will. Plus, since it is really affordable and easily attached to the top edge of the boxes, it won't be a big deal if Jill has to replace the trim pieces down the road.

Lumber is not the only issue, though. The previous boxes were built by someone else, and had been mainly nailed together, with the occasional drywall screw added for extra hold. 

Even though the flower boxes are stationary, they get a lot of wear from the weather and the fact that the soil they hold dries out and then gets soaked again over and over. Plus, the sun and temperature changes affect the boxes. It's a tough gig! 

So, nails aren't going to hold well over time and drywall screws aren't made for the outdoors. Many of them corroded and broke over time. Some kind of disintegrated. 

Jill chose to use a pin nailer to assemble her boxes temporarily, and then she went back and screwed them all together with outdoor-rated screws that are coated so they don't corrode. This made the boxes super solid and they should really stand the test of time.

To fit her 3-foot wide windows, Jill cut 3 pieces of 1x8 cedar to 35" lengths. She laid one flat as the bottom of the box, and then stood the other 2 up on edge along the the long sides of the bottom plank.  That gives you the front, back and bottom of the box. 

All you need now are the 2 short sides. Jill cut 2 more pieces to 6 3/8" and fit them into the ends. All you have to do, at this point, is screw the boxes together. As mentioned above, Jill used a pin-nailer to assemble the boxes first, and then screwed them together, but that nailing step isn't absolutely necessary.

Now, you got a great basic flower box that is ready to go. 

Jill wanted to go one step further to finish hers off, so she took some 1x2 pine and finished off the top edge, almost like a crown moulding. She laid it flat on the 2" side, mitered the corners, and nailed the inner edge of the pine to the top edge of the box, so that the pine 1x2 caps the edge and overhangs the front and sides of the box slightly.

Now you are done, and your flower boxes are ready to go!  Next week, Jill will show what she did to paint them, and how she found a better way to hang them on the house. 

PROJECT RATING: Medium - Medium+ (depending on the tools you have available)

To watch Jill take you through the process, just click on the video player above.