Question
QUESTION: Hi,
I'm re-using red bricks (8" x 4" x 2")to build small raised planter boxes.  I'm using them flat, so that a 6 brick high planter would be 12" high.  The boxes are square, with an interior diameter of approximately 22".  I'll be putting one small azalea bush in each box.  The planters are directly on the ground.
 My question:  Do I need to use mortar?  My thinking is that in ten-ish years the plant roots may push the bricks out.  Or, in place of mortar, could the box be lined with something, like metal flashing?  
 Many thanks for your help.

Bambi

ANSWER: You don't need to use mortar, which some folks are afraid of - You can use construction adhesive that comes in a caulk tube. Just leave some gaps for the water to escape. You don't need to caulk these things solid, just enough to keep them stacked.

I wouldn't "dry stack" them, as you are right; They're not going tostay put.  It is not just the roots, but water, and the "wiggle" of the bush over time, working against these bricks.

~Marc

---------- FOLLOW-UP ----------

QUESTION: Hi Marc,
 Many thanx for your encouragement and advice.  Obviously, this is my first experience with brick!  I'm not afraid of mortar--I tile floors, walls and ceilings in mosaic designs!  If it isn't right or I don't like the design, I get to do it over, so mortar is absolutely not a problem.
 Your advice brings up additional questions:
1. If I use the construction adhesive for brick, is the size of my planter limited?
2. At what size planter do I need to switch to mortar?     
3. Is there a glue specifically for exterior brick or a brand you'd recommend?
4. Does the adhesive, or should the adhesive leave a 'grout' space like mortar?
5. After all of these questions, should I just go with mortar initially??

I apologize for being such a pain in the pork chops, but that's just how my 'second grade' brain works!  Many, many thanx for your  advice and patience!!!

HUGE hugs,
Bambi


Answer
To your questions:

1. Not really limited to size.  Here in Nevada, there is a park (Sparks Marina) that has four 300-foot walls (1' wide x 4' tall) all held together with constuction adhesive.  Looks like you could just push it over - NOT!  I tried; It isn't going anywhere!  

Here is a picture of one of the walls in the background, next to the lake:
http://www.ci.sparks.nv.us/living/parks/marina/

2. It is up to you.  If you are matching existing brick, I'd use whatever the existing style is.  Mortar might be cheeper.

3. Retaining wall manufacturers offer adhesives for their "cap" stone courses.  Any of these would work just fine. (Available at Home Depot/Lowes)  

4. Usually, there are no grout spaces with adhesive method.  A slight "reveal" that is about 1/8" thick or less...Try not to over apply the adhesive.  Just enough to hold it together.

5. Personal preference (see question 2).  

Here are a few websites to help you decide:

Some examples of other people's brick planters (scroll throught he other pages for more pictures):

http://images.google.com/images?hl=en&q=brick+planter&gbv=2

The how to of mortar method:

http://www.doityourself.com/stry/brickplanter

~Marc