How do you make planter boxes?

[Ben Brantley]

Hi,

I've been making some cedar planter boxes to go on my deck rails. Unfortunately, my first three versions have all failed dramatically. The water seems to make the wood bend every which way, and no matter how many screws and glue joints I create, the box fails.

I don't understand how people make planters out of cedar unless (a) the wood I'm getting really stinks, (b) they don't actually put water in the planters directly, or (c) they use something besides this kind of wood.

??

Your thoughts much appreciated.

Ben

[Brian Loucks]

Hi Ben,
Did you drill a lot of drain holes in the bottom?
I built several window boxes using plain old butt joinery with white pine many years ago and they are still holding up very well. I also use plastic planters inside the boxes that are raised off the bottom an inch or so.
I reinenforced the inside corners with metal L brackets also.
Happy gardening.
Brian

[Ben Brantley]

Hi Ben,
Did you drill a lot of drain holes in the bottom?
I built several window boxes using plain old butt joinery with white pine many years ago and they are still holding up very well. I also use plastic planters inside the boxes that are raised off the bottom an inch or so.
I reinenforced the inside corners with metal L brackets also.
Happy gardening.
Brian

Hi Brian,

I did put three large holes in the bottom, yes. I also sealed the whole thing (obviously not very well) afterwards. I haven't used any plastic planters inside, and that may be my mistake -- but I was sizing the boxes for my deck rather than for the available plastic planters. I like the L bracket idea!

Ben

[Brian Loucks]

Ben, now that I think about it, I actually used 1/4" peg board for the bottoms. If the plastic box inserts don't fit your box dimensions, you can aways do as my wife did, add 6 " spacer pots to fill in with.
Brian

[Jim Tobias]

Ben,
I made several a couple of years back and they are holding up well. In making them , I left a gap or an inch or more between all rails on the sides, ends and bottoms. That left a lot of room for air to circulate. I used a vinyl screen wire and lined them on the bottom and side and ends. Stapled in the screen wire. Then filled them with good topsoil, a little "black cow" and planted. They drain well and have seemed to hold up well.

Jim

[Dewey Torres]

Ben,
Don't be afraid to post a pic of the failing boxes.

If you really want good advice, most of the folks here can sum up the failure for you much more accurately with a picture.

Now my turn to guess. Did you buy your cedar from one of the BORGs?

Dewey

[Matt Hutchinson]

I happened to catch some TV show making some HUGE window boxes. As suggested, some type of liner was their method. This particular show lined every thing with sheet copper! Hurts the pocket book just thinking about it!! You may be able to find something in the garden dept. of a BORG, but you also may be able to find something in the storage section, like a rubbermaid container. Also, I suppose you could use plexiglass, joining the edges with CA glue/epoxy and/or screw into wood corner blocks and seal with caulk.

As far as construction, you should post some pics. It may be a matter of using different joints, but the TV show supported their big window boxes with decorative wooden 'L' supports.

Hutch

[Greg Cole]

I've tried using a few liners for planters etc.
- Rubberized paint, like you put on tool handles. Worked ok, but not cheap. Available at any Borg.
- Hardi board with caulk on the joints. Works fine so long as you remeber the planter needs drainage. Was a great use of the siding scrap I had from installing Hardi lap and sheet siding to my home.
- Bare wood with water sealant & holes in the bottom. Seems to be fine for 3-5 years (then again some of these planters should be emptied and stored properly during the off season.).
I've all but gone the route that Brian's wife uses with plastic pots in the planters now, size them right and the pot is hidden, uses less water and you can move them all around to play with colors, whats blooming etc etc etc.
I usually screw things like this together and cover the screws with plug of the same wood & glue the plugs in place. FWIW, cedar isn't exactly well known for screw holding capacities even with prudent pre-drilling.

Cheers.
Greg

[Joe Chritz]

I expect that PVC liner sold for shower floor liner (for tile floor showers) would work for a liner. It would need to be fully covered with soil but I think you could staple it along the sides and it would work.

It wasn't really very expensive a few years ago when I built a shower using it.

Joe

[Lee Koepke]

EPDM flexible roof flashing would also make sense.

I think if you ponder it a bit, whats happening is the wood is absorbing moisture, swelling then drying out. That would cause the issue with fasteners. Even though your wood is exterior and may not rot, it doesnt mean its subject to natural properties of wood.

Its another of those projects I have on my (wifes) wish list, so if I am ever successful, I will be sure to share my secrets