Cheap Pot in pot setup.


LawnSite Member
Alberta, Canada
This is time consuming to set up, but I suspect that all PnP is.

I have a fairly porous silt+very fine sand subsoil. This will not work on clay.

I got a deal on a semi-trailer load of used 5 gallon pails that had drilling mud in them. Gross, disgusting, but largely harmless.

I have a groundhog H-99 auger.

A pail is a bit over 11 inches in diameter. A 10 inch auger usually ends up drilling a 12-13 inch hole. I've modified my auger to have a circular bubble level on back end of the hydraulic motor. Makes making a vertical hole a lot easier.

You will also need a supply of #4 or #5 injection molded pots. (the heavy ones, not the thin blow molded pots. A standard #5 pot is about 12 inches high. A pail is 16 inches high. You want 6" of pail sticking out of the ground. 12+16 -6 = 22 inches. This is the depth of your hole.

Auger your hole. Put the pot in upside down. Put the pail on top of it. Check that the pail is centred. (more on this later) Using a cordless drill and a speedbore bit drill several holes through the bottom of the pail and the bottom of the pot.

You now have a a 1 foot high bell under your pot for water to soak away. The space won't be troubled by pocket gophers.

Watering: Drill a 3/4" hole just under the rim of the pail. These can be not quite opposite (9:30 and 2:30) Snip a half inch of the rim by the hole. This supports your drip line. You really don't need to do this every pail. Every 3rd pail will do. If you don't have enough, what tends to happen is people (and dogs) will move a drip line off the top of the pots, and it catches on side.


In use:

The ideal is that the plant pot is about the same level as the dirt. The 6" raised part keeps most of the grass clippings out, and gives easy access to weedeaters. With a #5 pot, it fills the space inside the pail. Adding some mulch will seal the edge. The combination of pail and support pot conducts heat from the ground and keeps the plant from getting too cold.

This will accommodate most #5 pots (I have a bunch of Monrovia pots that go in, but are the very devil to get out.) Certain blow molded pots appear to work, but they can squish enough to sink. They too are hard to remove.

This will also accommodate using 5 gallon pails as pots. In this use, the dirt level is NOT even with the soil outside. This seems to work ok for trees that are one zone hardier than what you have locally. E.g. I have no problem doing this with white spruce (zone 2 hardy) in my zone 3 nursery. Of course if you do this, you need new holes.

You typically have to unclip for 3-4 pots in each direction to add or remove a pot.

Putting a small pot under the plant pot can prevent some of these issues.

Drippers are fussy, and get clogged for various reasons, either bugs nesting them, or grit. I use the cheap flag drippers as they are easy to take apart to work on. About once a month, I have my crew "Walk the lines" checking that drippers are operating.

Do not stretch the drip lines tight. They should be just snug when they have water in them. PE drip tube changes in length by about 2-3 percent between winter and summer. If you stretch it when installing it, it will pull out of the connectors in winter. If you have reason to want a less floppy setup on a warm day. (It will droop down, and get in the way of weedeaters...) string a line of high tensile fence wire, and fasten the drip line to the fence wire with black (uv resistant) cable ties.)

Drip line repair. The problem with a broken line is that by fixing it, you make the line shorter. You want to avoid broken lines if you can. Or you have to use 2 couplings and a chunk of extra pipe.

For reasons that escape me, something chews on my lines. Coyotes or my dogs. Haven't caught them at it. A temporary repair can be made with electical tape. It wont be water tight, but will reduce it down to about the same as another dripper. A more permanent repair can be made later using "shoe goo" (any running shoe store) and fiberglass reenforced tape. Sand the area with 80 grit sandpaper. Apply the goo to dry pipe and wrap as tightly as possible with strapping tape. This works on garden hoses too. I bet that silicone seal would work too. No glue really sticks to polyethylene, so you have to make mechanical join -- hence the sanding.

I tried one time to just run them 2 feet above the pots, figure it would be easy to walk the lines. Wind can blow the drops off the pots. Or grass will get a stem in the way. Or someone knocks the line sideways, and it catches on a branch. Or...

An alternate way to rig your lines: Drill 2 1/4 holes in the rim, and secure the drip line to the outside of pot. Place the dripper about 4 inches further along, and put a 12" chunk of 1/4" spaghetti tube on it. Drill another hole in the top of the pail and push the tube through so that it ends over the pot. These tubes are subject to problems with being pulled out when weeding around the pots, and take longer to set up.

A lot to be said for 2 drippers per pot. This reduces that chance that you lose a plant if a dripper gets clogged just after a line walk.

About pails:

95% of the pails I get are from 2 companies. The pails are not the same size. One type has 4 ribs at the top. The other has 3 ribs with the bottom one being curved. My crew call them 4 rings and hookers. There is about 1/8" difference in diameter. A hooker fits nicely in a 4 ring. A 4 ring jams in a hooker.

Not all pails are made from UV resistant plastic. Food grade pails almost never are. Petroleum product pails almost always are. Blue and black pails are usually more resistant than white yellow pails. Red pails only last 2 years. Pails that are not UV resistant get brittle and shatter at the slightest bump of a mower. If you realize that you have brittle pails paint the parts that see the sun.

I got 5000 pails for free from an drilling company. They are jammed together by the remains of the drilling mud, a slimey goo made of clay, sodium silicate, and soap. Having one crew member sit on the bottom end of the stack and grabbing the top pot with a pair of vice grips separates most of them. A small hole drilled in the bottom and an air compressor deal with most of the rest. The ulitimate way is a 3/4 hole on opposite sides of the bottom, with a steel bar run through. The bucket stack is then put between 2 fence posts set 1 foot apart. Pull on the top handle with a tractor. No handle? 3/4" hole on either side of the top, and a chain.

About holes:

It is surprisingly difficult to drill a straight line of holes. A tough clump of quack grass, a rock can push the bit to one side. I put a fence post at each end of the row, and stretch a line tight. From this I hang a light weight plum bob. If you hole is a bit large you have some shifting room to play with. You may want to use a 12" bit for this reason.

Kill the strip with roundup before you start. And/or till it.

A two person crew can set about 12 pails an hour. At $15 an hour that works out to about 2.50 per hole for labour. If you have a bobcat and auger, and can drill a hole where you want it, you may be able to speed this up a bunch.

I try to put my holes about 16" apart. This is enough to run a weedeater between them, or a wick weeder.

You can mark holes with spray paint, but this is either too big and sloppy at 2-3 inches across, or too hard to see. I used a scrap of electrical conduit to put a hole in the ground, then stuffed a Kleenex in. This is very visible until the next rain, and vanishes when the hole is drilled. You can use flagging tape, or grocery bag plastic for something that lasts longer.


LawnSite Member
Alberta, Canada
When marking the holes: Jam the electrical conduit in, and wiggle leaving a 4" deep 2" wide hole. This makes a nice pilot hole for the auger tip, reducing skittering.