spray on stucco for raised bed

I will soon start on my earth bag raised beds.  I expect them to be about 2 foot tall.  Part of making things easier for retirement. Got this idea from Dr. Redhawk.

I would like to use a stucco or cement sprayer but only have a 6.5 CFM at 90 PSI sprayer.

I can get the stucco fiber mesh and wire it onto the bags before spraying.  I will add some cement coloring to make it look better.

Any recommendations for sprayer models and mix ratios?  I would like to do this in one application.  

I am in Zone 7B with a lot of rain.  It gets down to 10F and up to 100F.
 

So I tried to do this with a sprayer on my ferrocement beds and it did not work as well as I would have liked. Plaster everywhere. I went and did it by hand and it was much more effective. How many feet of bed do you have?

The first bed for my blueberries will be around 20ft by 12ft. They are in wicking beds and I want to make sure the roots don't freeze.  Others will be longer and narrower (4ft by 30ft) I am planning on several.  What brand did you use?  Did you spray close and thick or farther away to get a thin coat?

I used the Eco-worthy 4 jet stucco sprayer and sprayed pretty close because I was going thick and was going to trowel afterward. I just felt like too much material was being wasted falling to the ground.

what size was your compressor?  Most say 7cfm or greater but there is one that can use 4 to 6 cfm with the smaller jets.

There are a couple DIY versions on YouTube, and several that you can plug jets or make smaller jets.  

Best thing to make a small compressor act like a big one is to get a bigger tank.  Buy or scrounge a broken compressor with a good tank and plumb the tank in for more surge capacity.  It makes a HUGE difference.  And the biggest and shortest hoses you can.  We usually put the compressor as close to the outlet as we can, then run big hose to the surge tank, which is as close to where we are working as we can, and then a short lighter hose to the tool.  The compressor runs better on no extension cord, it is quieter at the jobsite, and the tools get all the air they need.  The air is cooler and dryer by the time it gets to the tool, so things liked nail guns and impact wrenches are happier as well