I noted this has sat without an expert answer, so I'll give it a whirl. I've DIY-ed on my own irrigation system, several others, done pots, and had a great deal of fun with cutaway water distribution and (most recently) wicking tests just to see what's up with all the hoopla. I sleep little and think too much, apparently.

That's...certainly going to keep it damp efficiently. And I'm going to say that if it works for you, I'm not here to discourage you from using this. It's going to efficiently damp the soil pretty quickly on a short run, and if you have the water pressure to handle all this (with minimal output and/or few pots, not a problem), then by all means, go for it.

It is, however, kind of a pricey solution in terms of dripper lines and you can certainly get away with far less.

The technical recommendation is usually 1 half gallon per hour dripper per pot 10 inches or less, 2 up to 15". 4 for 16-18".

Personally, I would recommend using 2 half gallon per hour drippers minimum in a pot of any size over six inches. One, it distributes the water a bit better. Two, if a dripper clogs, the other one is there to pick up the load, at least partially (and choose self-cleaning drippers if you can). I don't feel that three is an unreasonable number if the person wishes to use that many, distributed roughly evenly a third of the way around a pot.

For 5-1-1 mix, it can depend a tad more on how you're watering. If you let it dry very thoroughly, it can get a bit hydrophobic and refuse to get damp. In that case, yes, you can end up with wet and dry pockets, and it can take several waterings over a period of time to get the entire pot damp unless you're using some minor chemical tricks like a drop or two of soap per gallon of water to change the viscosity and absorption characteristics (and even then, it's not always a simple process).

Let's just choose the simple way out and say there's no real easy way around that other than careful and certain watering, but two to three drippers certainly is not going to induce a major issue there (been there, done that, got the T-shirt). Water wicks around just through the capillary action of the soil, air pockets, and bark. Stuff gets wet. You know the drill.

So I'd be more inclined to go with three on 5-1-1 mix on a 10 inch pot, possibly up to 4 on a 12 inch. Maybe even 6 on a 15-16" pot. But really, that should be sufficient, particularly at half a gallon an hour.

Umbrella drippers would be another possibility, but would have to be stuck into the soil and would impede bringing them in easily as they'd have to be removed, so I think I'd just go with the drippers I see there, just a lot fewer of 'em. :-) Remember to compensate with longer watering, of course. And you already own those drippers, so why not keep it cheap?

Travis what I do is take a piece of the emitter tubing similar to what you are using that has a 6 inch spacing between the emitters and cut a piece that has 3 -4 emitters on it depending on the size of the pot but usually 4. Then put a goof plug in one end

andThe output side of a .5 GPH Netafim Emitter on the other end. The input to the netafim is fed by the supply tubing for that pot . I take and make a loop around the plant with the 4 emitter drip tubing and hold it in place with staples. As the plant grows and the weather gets hotter you can change out the .5 GPH emitter with a 1 GPH you can also easily remove it by pulling up the staples.

When I get a chance I will take a picture of one and you can see exactly what I am talking about as a picture is worth a thousand words.

Thank you morpheuspa and familyman. If I'm understanding correctly, you both are advocating for a very similar approach, namely, to use my existing line with embedded drippers, but it could be scaled back to 4-6 emitters instead of the gazillion I have on the lines. I would probably just make a single loop that contained enough.

That was my initial plan but I worried the water would run right down. Morpheuspa indicated capillary action and such would help distribute the water. I thought it would do that but I installed these the night before a big trip so I didn't want to take the chance. I'm home for a week so maybe I'll trim the lines down and observe.

Exactly, we're pretty much coming from the same place and saying you're on the right track, but if this is hard to move for you when you have to, trim it down. Three, four, six, whatever's easy for you to put in and take out when you have to.

And yep, capillary action will carry the water around. Yes, there's a minimal number for a very large pot; I consider it about 3 in very sandy soils in the very largest pots. 5-1-1 isn't the sandiest, it has a good component of soil and organics, nothing like the stuff my desert roses sit in. :-)

By all means, check your soils. If they're too dry, add one or two more. Don't be afraid to modify! I shift my gardens around every time I redesign them, which is yearly.

I am not qualified enough to give you the right answer. But I have put adjustable sprinkler heads on a stick in the pots. I can twist the sprinkler head to control the radius so that it stays in the pot. So far it has worked very well in Australia summers. My plants are in 511 mix.