Tips for Sealing Indoor and Outdoor Planter Boxes

I built these DIY Herb Planter Boxes a few years ago. Originally I used them as an indoor herb garden in my kitchen. Last week, I purchased a couple of rocking chairs for my deck and they match the stand perfectly. So I’ve decided to move the stand and boxes out on my deck and use them for flowers. I knew this move would involve sealing the planter boxes.

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Since this is a different application, I needed to drill drainage holes and seal the pine to help preserve it. I’ve written a quick DIY tutorial below on how I prepared them for indoor and outdoor use.

A couple of notes before I begin. First, I built these boxes out of leftover common pine boards. This was a quick and cheap way to use up the supplies I already had. If I were planning this project from the beginning, I would use pressure treated lumber or cedar fence pickets.

Second, these are very easy to build. There are already a bunch of good tutorials on the process, so I didn’t include a tutorial for building them. If you’re looking for a tutorial to build them, a good place to start is here.

Third, the white stand was purchased two years ago at TJ Maxx. I built the boxes to fit the stand.


I used these kitchen herb boxes for a couple of years before moving them outside. To keep them from leaking, I used wood glue on all of the joints when assembling them. Then, I caulked all of the cracks with Silicone Kitchen and Bath Caulk. Next, I sealed the wood on the inside of the box with polycrylic. Finally, I hot glued landscape fabric to the inside of the box. I tested them for about a week on a piece of cardboard, just to be sure they wouldn’t leak. I recommend you do the same. Take care not to over water them, because there is no drainage. Put some rocks in the bottom, before adding the soil, to prevent root rot.

Sealing DIY Wood Planter Boxes


When I decided to move these outdoors, I drilled drainage holes in the bottom of the boxes. After researching different products, I settled on Minwax Water Based Helmsman, for the protective finish. It comes in a satin clear finish and offers protection from sunlight, rain/moisture and temperature changes. The directions recommend applying it with a synthetic brush. For exterior surfaces it recommends four coats. You should let the product dry for 2 hours and then lightly sand with a 220 grit paper in between coats.

I plan to use this product on a few exterior projects. I’ve never used it before, so I cannot comment on its performance. It did get good reviews when I researched it.

Wood will weather in an outdoor environment and untreated wood will weather quickly. Hopefully this will slow the process down.

Sealing DIY Wood Planter Boxes

If you are interested in the free JPEG or SVG Cut Files I used for this project, they are available here. If you subscribe below, the password will be sent to your inbox for access to the free printable and cut file library.

Here’s an image to pin for later use.

Sealing DIY Wood Planter Boxes

I hope these tips helped you with sealing planter boxes or other wood projects! Let me know if you tried it in the comments.






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