Wheel and hand-building technique
Planters With an Attached Drip Tray
A saucer you can lift has one job: you pour it out. Attach it and you have taken that job away, so the water has to live somewhere on the pot instead. Where you put it is decided by one measurement, and you make that measurement long before you cut a single hole.
Jump to a section
One object, two jobs. The hard part is the half inch you cannot see.
The short version
Two facts, and the rest is ordinary throwing
The whole design, in one line
Make the step half an inch, and make the moat wide enough to hold a cup of water. Everything else about this form is a normal pot.
Fact one is the step. The planter’s floor has to sit about half an inch above the floor of the tray, so water runs downhill on its way out and then sits below the soil instead of against it. A tray level with the pot floor is a decoration.
Fact two is where the holes go. On a planter thrown in one piece, the drains go through the wall at floor level, not through the bottom. The pot floor and the tray floor are the same continuous slab of clay, so a hole in the bottom drains onto your table. Cut three or four holes, 3/8 in each, through the wall right where it meets the floor, at leather hard.
Two things that will wreck it if you do not know them. Throw it on a bat and never wire it off, because a wide thin flange will not survive being slid. And when it dries, put plastic on the tray and nothing on the pot, so the thin fast half waits for the thick slow half. Skip that and it cracks in the corner of the moat, which is where these always crack.
Then, weeks later at the glaze bench: clear every drain with a damp paper towel from both sides, because glaze bridges a small hole and turns to glass at cone 5½. And when you plant it, no gravel in the bottom. It does not help and it slightly hurts.
01 · The one idea
The water has to end up somewhere you can see it
The question the whole page answers
How far above the tray floor does the planter’s floor sit? Call it the step. If the step is zero, water sits back against the soil and the tray is an ornament. Half an inch of step is the difference between a planter and a decoration, and you set it in the first five minutes of throwing.
A loose saucer does exactly one thing, and it does it so easily that nobody notices it happening: you pick it up and you tip it into the sink. Every question about drainage answers itself, because the water leaves the building.
Attach the saucer and that is gone. The water is now a permanent resident of the pot. It has to sit somewhere that is lower than the soil, visible from outside, and reachable with a sponge. Three requirements, and the shape of the piece has to satisfy all three at once.
Which leads straight to the thing that surprises almost everyone who makes their first one. On a planter thrown in a single piece, the drainage holes do not go through the bottom. They go through the wall, right at floor level, and they let water walk sideways out of the pot into the moat. A hole in the bottom of a one-piece planter drains onto your table, because the pot floor and the tray floor are the same continuous slab of clay.
Once you have seen that, the rest of the form stops being mysterious. The planter’s floor has to be raised so the water runs downhill on its way out. The moat has to be deep enough to hold a normal watering below that floor. The lip has to be tall enough to keep it in. That is the entire design, and everything below is how to get it built without cracking it.
02 · Why this page reads like this
Watching teaches your hands. Reading is what you can check.
There are seven very good videos further down this page, made by people who are better at this than we are. So it is a fair question why anybody would read about it as well.
Because the two are good at different halves of the job, and this particular form splits along that line more cleanly than most.
What a video does better
Hands. How hard you lean on a rib to compress a wide floor, how fast the wheel is actually turning, what splitting a mound with the side of your hand looks like from the potter’s side. Nobody has ever written a sentence that teaches those, and nobody ever will.
What a page does better
Where the hole goes. That is a decision, not a motion, and it happens off camera at leather hard a week after the video ended. Watch six planter videos and you will still not know whether the drains went through the wall or through the floor.
There is a second thing text is better at, and it is a boring one: waiting. A video plays at its own speed and does not care that your hands are covered in slip. A page sits perfectly still and is exactly where you left it when you come back. That is the difference between being shown something and learning it.
The part that actually convinced us
Watching somebody good throw one of these is persuasive and slightly dishonest, through no fault of theirs. You are watching an edit. The four minutes of measuring, the week of drying, the ten seconds where they decided where the holes go, all of it is cut, because none of it films well. You finish the video certain you understood it. Then you sit down at a wheel and discover that what you retained was a feeling rather than an order of operations.
So this page is written to be read at the wheel, on a phone, in short lists you can look at with one wet hand. Every video on it is here because it shows something the words genuinely cannot.
Read it through once. Watch one or two of the videos. Then keep the checklist open while you work.
03 · Three routes
Three ways to build one, and what each costs you
All three end at the same geometry. They differ in where the difficulty sits, and none of them is the beginner option, so pick the one whose hard part you would rather have.
One piece, one lump
Center a low wide mound, split it into an outer ring and an inner core with the side of your hand, throw the ring flat into a tray and the core up into a planter. It never comes apart because it was never apart.
Good at
No join to fail, no drying mismatch, and it looks like one object because it is one.
Costs you
You have to hit the step by eye and by needle tool while the clay is soft, and you cannot trim the underside afterwards. Get it wrong and there is no fixing it.
Two pieces, joined at leather hard
Throw an ordinary planter and an ordinary shallow saucer. Trim the planter a foot ring, notch the ring, then score, slip and press the two together while both are soft leather hard.
Good at
Total control. You can trim the planter normally, cut a conventional hole in its floor, and measure the step with a ruler instead of a guess.
Costs you
A join that runs all the way round the piece, in the exact place the drying stresses concentrate. It is the most common place these fail.
Slabs
Roll a slab, cut a tray, cut a cylinder and a floor, assemble. Square and oval versions only really happen this way, and so do most of the interesting ones.
Good at
The step becomes a number you cut rather than a thing you judge, which is a real advantage on the one measurement that matters most.
Costs you
Far more seams, and flat slab floors warp harder than thrown ones. Every corner is a place a crack can start.
One geometry that does not work, in any route
A hole in the middle of the planter’s floor, with a solid unbroken joint between the pot and the tray. The water leaves the soil, arrives in a sealed chamber under the pot, and stays there for the life of the plant. You cannot see it, you cannot reach it, and the roots sit in it. If your design has a central hole, the pot has to stand on a notched foot so the water can get out to the ring you can see.
04 · The anatomy
The anatomy
The whole thing in cross-section
Cut one in half and every decision on this page becomes visible at once. This one is drawn to scale: a nine inch tray, a six inch planter, and a half inch step.
Cut one in half and the step stops being an abstraction. Drawn to scale: a nine inch tray, a six inch planter, and a half inch step.
- 1The lip. The only thing holding the water in, and the thinnest, most exposed edge on the whole piece. Bevel it while it is wet and never rest the pot on it.
- 2The moat. The low ring around the planter. This is the tray. Everything the tray is for happens in this space.
- 3The step. How far the planter’s floor sits above the moat floor. Half an inch here, and it is the single measurement the piece succeeds or fails on.
- 4The side drains. Cut through the wall at floor level, not through the bottom. Water crosses sideways out of the soil and falls into the moat.
- 5The junction. Where the wall lands on the tray floor there is more clay than anywhere else on the piece. Cut the excess out and compress the corner, or it cracks.
- 6The underside. One flat foot, the full width of the tray. It sits on the kiln shelf, so it gets no glaze anywhere.
05 · The numbers
Numbers to start from, not rules to obey
Sizes are the planter’s outside diameter. Everything here is wet-clay measurement, before shrinkage. Our clay bodies shrink somewhere between about ten and fourteen percent depending on the body, and the whole piece shrinks together, so the proportions hold and only the absolute sizes move.
| Measurement | Small, 4 in planter | Medium, 6 in planter | Large, 8 in planter |
|---|---|---|---|
| Tray outside diameter | about 6 1/2 in | about 9 in | about 11 1/2 in |
| Moat width, each side | 1 in | 1 1/4 in | 1 1/2 in |
| The step | 3/8 in | 1/2 in | 5/8 in |
| Lip height above the moat floor | 1/2 in | 5/8 in | 3/4 in |
| Water it holds to the step line | about 3 fl oz | about 8 fl oz | about 15 fl oz |
| Side drains | 3 holes, 5/16 in | 4 holes, 3/8 in | 5 holes, 3/8 in |
| Clay for the one-piece version | 2 to 3 lb | 4 to 5 lb | 8 to 10 lb |
Why the lip is taller than the step, but only just
The moat’s useful depth is the step, not the lip. Water above the step line is already touching the planter’s floor and wicking back into the soil. The extra eighth of an inch of lip is a splash guard and a margin for a wobbly table, not extra capacity. Build the lip much taller than that and you have made a bucket that quietly floods the pot from below.
Eight ounces is about one watering
A cup of water is roughly what runs through a six inch pot of dry potting mix when you water it properly. That is not an accident in the table above; it is where the numbers came from. If your moat holds noticeably less than one watering, you will be sponging it out every single time, and you will stop doing that by about week three.
Shrinkage figures for every body we stock are on the clay and pottery calculators page.
06 · Route one
The method
One piece, one lump, in nine steps
One piece, one lump, in six steps
Before you sit down
Put a bat on. Not a suggestion. The finished piece is a wide thin flange sitting on the bat head, and there is no way to wire under it and slide it off without distorting or tearing it. If you are undecided about bats generally, this is the form that settles it: bat or no bat.
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Center low and wide
Four to five pounds for a six inch planter, coned once and then pressed down into a broad dome no more than about two inches tall. You are about to spread this clay outward, not lift it, so a tall centered mound is working against you from the first minute.
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Split the mound into a ring and a core
Press the edge of one hand straight down into the top of the dome, about an inch in from its outside edge, all the way to the bat. Keep the wheel slow and your elbow braced. You now have an outer ring that is going to become the tray and an inner core that is going to become the planter.
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Throw the tray first, while you can still reach it
Work the outer ring outward and flat with the pads of your fingers, keeping it a steady quarter inch thick. Stop when the flat ring is as wide as the moat plus the lip. Then turn the last half inch up into a low wall. Do this before you touch the core, because once the planter is standing you cannot get a hand in there.
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Compress that floor, then compress it again
A wide flat disc is the most crack-prone thing you can make on a wheel, and the tray floor is a wide flat disc with a pot standing in the middle of it. Rib it firmly from the center outward, twice, and mean it both times. There is more on why in compressing the floor and the rim.
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Open the core, and set the floor high
This is the step, and it is the moment the whole piece is decided. Open the core, but stop with its floor a full half inch above the tray floor. Check it with a needle tool: push through to the bat inside the pot and again out in the moat, and compare. Do not guess this. Guessing it is the single most common way one of these ends up a decoration.
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Pull the walls
Two or three slow pulls, outside kept plumb or gently flared. Keep your pressure high on the wall and off the base. Every pound of downward force you put near the bottom is force going into the junction and the tray floor, which are already the two most stressed places on the pot.
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Cut the junction back
Look at where the wall lands on the tray. There is now a fat wedge of clay in that corner, thicker than anything else on the piece, sitting directly against a thin flat flange. Thick beside thin is how pots crack. Take the excess out with a wooden knife, then compress the corner into a clean small radius with a rounded rib.
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Finish both rims
The planter has a rim and the tray has a lip, and people forget the second one every time. Compress both with a chamois or a wet finger. While you are there, check that the lip is only a little taller than the step. Much taller and you have built something that can back water up into the pot.
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Take the bat off with the pot still on it
Do not wire it. Do not slide it. Lift the whole bat off the wheel and carry it to the shelf. This piece stays on that bat until it is leather hard, and honestly it is easiest to just leave it there until it is bone dry.
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Center low and wide on a bat
Four to five pounds for a six inch planter, pressed down into a broad dome no more than about two inches tall. You are going to spread this clay outward, not lift it. The bat is not optional: this piece can never be wired off.
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Split the mound into a ring and a core
Press the edge of one hand straight down into the top of the dome, about an inch in from its outside edge, all the way to the bat. The outer ring becomes the tray. The core becomes the planter.
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Throw the tray flat, and compress it twice
Work the outer ring outward to a steady quarter inch thick, rib it hard from the center outward two full passes, then turn the last half inch up into a low lip. Do all of this before you touch the core, because once the planter is standing you cannot reach in there.
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Open the core with its floor half an inch high
This is the step, and it is the moment the piece is decided. Stop with the planter’s floor a full half inch above the tray floor. Check it with a needle tool: push through inside the pot, then out in the moat, and compare. Do not guess this one.
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Pull the walls, then clean the corner
Two or three slow pulls, keeping your pressure on the wall and off the base. Then cut the fat wedge of clay out of the corner where the wall lands on the tray, and compress that corner with a rounded rib. Thick beside thin is how this form cracks.
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Finish both rims and carry the bat away
Compress the pot rim and the tray lip, and bevel the outside bottom edge with a wooden knife while you still can. Then lift the whole bat off the wheel with the pot still sitting on it.
07 · Route two
Two pieces, joined at leather hard
The rule that makes joins work
Both halves live the same life. Same clay body, same bag if you can manage it, same session, same shelf, under the same plastic, for the whole time they are stiffening. Two pieces only shrink into each other if they start at the same wetness, and a join between a soft pot and a stiff saucer will open in the kiln every time.
This route trades a harder throw for a harder join, and for a lot of people that is a good trade. Nothing about either pot is unusual, and you get to measure the step with a ruler instead of a needle tool and a hope.
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Throw an ordinary planter
Straight-sided or flared, whatever you like. Give it a base wide enough to carry a pot of wet soil without tipping, and leave enough clay in the bottom to trim a foot ring later.
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Throw a shallow saucer
Flat floor, low wall, and an inside diameter at least two and a half inches wider than the planter’s foot, so you finish with well over an inch of visible moat on every side. Compress the floor hard. Wide flat things crack.
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Stiffen them together
Same shelf, one sheet of plastic over both, until both are soft leather hard. Soft, not firm. A join made at firm leather hard is a join you will be able to find with your eye after the glaze firing.
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Trim a foot ring you can cut into
A quarter inch tall is plenty, and the ring wants a decent flat width to it, because that flat is the only thing gluing the whole piece together. Trimming and turning covers the tool work.
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Notch the foot ring
Three or four gaps cut clean through the ring, each about three eighths of an inch wide, evenly spaced. This is the part people skip and it is the part that matters. Without notches the water leaves the soil, arrives under the pot, and lives in a sealed chamber for the rest of the plant’s life.
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Cut the drainage hole
One half inch hole in the middle of the planter’s floor covers anything up to about six inches across. Cut from the inside out, then clean the burr off the underside with a damp sponge.
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Score, slip, press, twist
Score both surfaces properly, slip both, press them together and twist a quarter turn so the slip keys in. Then weld a thin coil into the inside corner all the way round with a rounded tool. The corner weld is not decoration; it is most of the strength. Full method on scoring and slipping joins.
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Dry it slower than you want to
Loose plastic, a week, and check the inside corner before it goes to bisque. That corner is where a two-piece version fails, and a hairline you can see at bone dry will be a real crack after cone 5½.
08 · Route three
Building one from slabs
The advantage nobody mentions
On the wheel the step is a judgement you make in wet clay with a needle tool. From slabs it is a number you cut with a ruler. If the half inch is the thing you keep getting wrong, this route hands it to you for free.
Everything on this page about geometry applies unchanged. Only the tools are different, and the failure modes move from the throwing to the seams.
Roll one slab for everything and let it stiffen to soft leather hard before you cut. Cut a tray floor, a tray wall as a long strip, a planter floor and a planter wall as a second strip. Build the tray first, flat on a board. Then stand the planter’s wall on the tray floor, inside it, and set the planter’s own floor half an inch up inside that wall rather than resting it on the tray. That half inch is the step, and here you simply measure it.
Every seam gets scored and slipped and then welded with a coil from the inside, including the one you cannot reach comfortably, which is the one that will fail if you leave it. Cut the side drains through the planter wall at floor level once the whole thing has firmed up a little more.
Two warnings specific to slabs. Flat slab floors warp harder than thrown ones, so dry the whole assembly flat on a board, slowly, and resist picking it up to look at it. And square trays crack at the corners, because a corner is a stress concentration with clay on two sides of it; round every internal corner generously with a rounded tool.
If you are new to slab work, start with the slab roller and slab molds and getting the best results from our slab molds. Coil-built versions work too, and blending coils covers the joins.
09 · Leather hard
You cannot flip this one over
Why not
Turn an ordinary pot upside down and it rests on its rim, which is compressed, round and built for exactly that. Turn one of these upside down and it rests on a quarter inch flange of flat clay that is the widest and thinnest edge on the piece. It chips, it cracks, or it goes oval, and you will not always notice which until after the glaze firing.
So the honest answer for most people is the one nobody likes hearing: do not trim it at all. Finish the underside on the wheel while it is still wet and still on its bat, and you have nothing left to do later except the holes.
That means a wooden knife bevel around the outside bottom edge before you take the bat off, and a rib pass to clean the outer face of the lip. Thirty seconds of work at the wheel that saves you an impossible job a week later. If you do need to tidy the underside, put it right side up on a pad of soft clay or a piece of dense foam, run the wheel slow, and only touch the outer edge.
Cutting the drains
- Wait for firm leather hard. Softer than that and the hole closes behind the tool; drier and the wall chips out on the far side.
- Mark them first, evenly spaced round the wall, sitting directly on the planter’s floor so no water is left stranded above the hole.
- Cut from the inside out, with a hole cutter or a drill bit turned by hand. A twisting motion, no pushing.
- Angle each one very slightly downhill toward the moat. A level hole works; a downhill hole drains the last teaspoon out of the pot.
- Clean the burr off both faces with a damp sponge and a fingertip. Burrs on the inside collect roots and burrs on the outside collect glaze.
- Cut 3/8 in and you will have roughly 5/16 in after firing, because the hole shrinks along with everything else.
The same tools and the same timing work for any hole in any pot, and there is a lot more detail on all of it on making ceramic kitchen strainers, which is a page about almost nothing except cutting clean holes in clay.
10 · Drying
The crack forms in the corner, and it forms while you are asleep
Cover the tray, not the pot
Every instinct says to wrap the whole thing. Do the opposite. Lay strips of plastic over the tray lip and the moat and leave the planter’s rim open to the air. You are not slowing the piece down, you are slowing the fast half down so the two halves arrive together.
Nothing about this form is more likely to ruin a good week’s work than drying it the way you dry a mug.
Here is the physics, and it is not complicated. The tray flange is thin, flat, and exposed to moving air on its top face and its outer edge. The planter wall is thicker, and it is partly shielded by its own shape. They dry at genuinely different speeds. Clay shrinks as it dries. Two pieces of one object shrinking at different rates pull against each other, and the pulling concentrates exactly where they meet, which is the inside corner of the moat.
That is why the crack is always in the same place. It is not bad luck and it is not the clay. It is a drying rate problem with a drying rate answer.
What actually works
- Leave it on its bat. Moving it is when it flexes, and flexing a wide flange at leather hard is how a hairline starts.
- Plastic over the tray, nothing over the pot rim, for the first two or three days.
- Give the whole thing a week to bone dry, not two days. It is a bigger footprint of flat clay than almost anything else you make.
- Keep it off the heater vent and out of a draft, which for a piece this flat means not on the end of a shelf near a door.
- Look at the inside corner of the moat before it goes to bisque, in raking light. A hairline you can see now is a real crack after the glaze firing, and it is easier to hear about it from us than from the kiln.
If a bottom has come out thinner than you meant it to, or you find a crack early, fixing a bottom thrown too thin covers what is and is not worth attempting.
11 · Glazing
Four ways glaze ruins one of these
Do the moat first
Before anything else, before you dip, before you think about the outside, glaze the inside of the tray. It is an awkward ring to reach with a brush and an impossible one to reach once the outside is coated and you are trying not to touch it. Two coats in the moat, then everything else.
- It plugs the drains. Glaze runs into a 5/16 in hole, bridges across it, and at cone 5½ that bridge turns to glass and never opens again. After you glaze, roll a damp paper towel or a wooden dowel through every hole, from both sides, and hold it up to the light.
- It pools in the moat. The moat is the lowest ring on the piece, so anything that moves in the firing collects there. Best case it fills the moat with glass and you lose the capacity you built. Worst case it runs over the lip and welds the whole thing to the kiln shelf. All four of our flux glazes move, and Running Hot Chowder moves the most; keep them off the inside of the tray entirely and start them well above the lip on the outside.
- It reaches the shelf. The underside of the tray is one big flat foot and there is no way to stilt this form. Wax it, wipe it, and keep glaze back a good quarter inch from the bottom edge on every surface, including the outside of the lip where a drip will find its way down.
- It never gets in the moat at all. Which is the quiet failure. Bare stoneware in standing water will not leak at cone 5½, but it stains, it grows a ring, and it is unpleasant to clean. See the callout: moat first.
If you are dipping rather than brushing, remember the piece now has holes in it. It fills, it traps air, and it dumps glaze in the wrong direction when you lift it. Plug or tape the drains for the dip and clear them properly afterwards. There is a video further down of a potter who built a tool for exactly this problem, which tells you how common it is.
The inside of the planter is your call
Glaze it and it is easier to clean and it will never weep. Leave it bare and people will tell you the wall breathes. Both camps are less right than they think: our stoneware fired to cone 5½ is close enough to non-porous that the breathing argument barely applies. Do whichever you like the look of, and keep glaze out of the drains either way.
More on all of this in using dipping glazes, and the glaze finder will tell you which of our glazes move before you commit one to a moat.
12 · The honest bit
The tray more than doubles the firing
Nobody tells you this before you throw a twelve inch one
We charge for a glaze firing by the box your piece occupies, measured at its widest points, at five cents a cubic inch with a $4.80 floor. Bisque firings are free, every time. That pricing is perfectly fair and it is also brutal to a shape that is much wider than it is tall.
Take a six inch planter, six inches tall. On its own that is a six by six by six box: 216 cubic inches, about $10.80 to glaze fire.
Now stand that same planter on a nine inch tray. The pot has not changed at all. But the box is nine by nine by six now, which is 486 cubic inches, and the firing is about $24.30.
Nothing was added to the pot except three inches of flat clay you can barely see from above, and the firing went up by roughly thirteen dollars. Scale that up and it gets steeper fast, because two of the three dimensions grow at once. This is worth knowing before you decide the eleven inch version is the one you want.
None of which is a reason not to make one. It is a reason to make your first one small, find out whether you like living with the form, and then make the big one on purpose. Run your own measurements through the firing calculator before you commit a whole afternoon to it.
13 · Watch it happen
Watch it happen
Seven potters, and not one of them us
Two videos, then go and throw one
Grouped by what they teach rather than by who made them. Watch whichever one covers the part you are least sure about. Nothing loads until you tap it.
Three minutes to see the shape of the move, and sixteen to watch it properly when you have time. Neither loads until you tap it.
How To Throw A Pottery Planter With An Attached Tray
Matthew Kelly Pottery
The most complete one-piece walkthrough we could find, and it is long enough to actually show the boring parts. He splits the mound, throws the tray first, and talks through the junction while he is cutting it back. If you watch one thing before you sit down, watch this. Watch it on YouTube.
Throwing A Planter With A Built-In Tray On The Wheel
The Clay Collective
The whole move in under three minutes, no talking, no preamble. Useless as a first lesson and excellent as a reminder five minutes before you throw one. Watch it twice at half speed and you will see the hand-split clearly. Watch it on YouTube.
For My Pottery Students. Throwing a small bowl planter with attached saucer, using 1 lb of clay.
Barbara Dunshee
Recorded for her own students, which is exactly why it is good: she explains the things a class actually asks about rather than the things that look impressive. One pound of clay, so it is a cheap way to make your first four. Watch it on YouTube.
For my students. Trimming the small planter with attached saucer.
Barbara Dunshee
The follow-up to the video above, and close to the only footage anywhere of somebody dealing with the trimming problem on camera. Watch what she does and does not touch. This is the part of the process every other tutorial cuts. Watch it on YouTube.
Wheel Throwing a Medium Sized Planter with an Attached Drainage Plate on the Wheel | Pottery by Sara
Sara Flynn
A different opening move from the hand-split: she spreads the whole thing wide first and raises the wall out of the middle. Worth watching straight after Matthew Kelly so you can see the two approaches to the same form back to back. Watch it on YouTube.
Dip Glazing Planters with a HOLE - custom glazing tool
Pottery by Kent
Seven minutes on the one problem no throwing video mentions: a pot with holes in it does not dip like a pot. He built a tool to solve it. Even if you never build the tool, watching the failure he is solving will save you a piece. Watch it on YouTube.
How to slab-build a ceramic planter
Pottery Templates
The hand-building route, template first. He is not building an attached tray, so treat it as the assembly lesson and bring the geometry from this page: raised floor, side drains, welded corners. Watch it on YouTube.
14 · Afterwards
Afterwards
The part nobody mentions: you cannot pour it out
Keep a baster with the plant
A cheap turkey baster or a bulb syringe empties a moat in about four seconds and is the single thing that decides whether somebody keeps using one of these or quietly moves the plant into a plastic pot. A sponge taped to a chopstick works too and costs nothing.
This form is genuinely lovely and it has real drawbacks, and we would rather you heard them from us than found them out in November.
- You cannot tip it. Water in smaller amounts, more often, or water into the moat and let the pot wick it up from below. Both work. Flooding it and walking away does not.
- Never leave it full to the step line. Water sitting at the step is water touching the planter’s floor, and the soil will drink it straight back. The moat is somewhere to see water, not somewhere to store it.
- It is an indoor object. Outdoors in the open, rain fills the moat and it has nowhere to go, so the plant sits in a puddle for the whole wet week. A covered porch is fine. An open patio is not.
- Bring it in before the first hard freeze. This is Utah. Water in a moat that freezes expands and splits the tray, and it will always split the thinnest part, which is the lip you spent the longest on.
- It is heavy. Wet stoneware plus wet soil plus a wide tray is a genuinely two-handed object at eight inches. Decide where it is going to live before you decide how big to make it.
And then the reason to make one anyway.
It never slides off its saucer. It never leaves a ring on the table because the saucer wandered an inch to the left. It gets picked up as one thing and put down as one thing. And it reads as a single designed object rather than a pot resting on a dish, which is the whole point and is worth the sponging.
15 · Troubleshooting
Troubleshooting
Nine ways this goes wrong
The three that get you on the first one
Every one of these has happened in this building. Most of them are decided long before the thing that goes wrong becomes visible, which is why they are worth reading before rather than after.
All three are decided at the wheel, hours or days before anything looks wrong. That is exactly why they are worth reading first.
A crack in the inside corner of the moat
The most common failure by a distance. Either the junction was left thick against a thin flange, or the tray dried faster than the pot. Cut the corner back on the wheel and compress it, then cover the tray and not the pot while it dries.
An S-crack across the tray floor
The wide flat floor was never properly compressed, so the clay platelets never got knitted together across the middle. Rib it hard from the center outward, twice, before you open the core. There is no fixing it afterwards.
The tray came out warped
It dried unevenly, or it got flipped over for trimming and rested its whole weight on the lip. Dry it flat on its own bat, and finish the underside while it is still wet on the wheel instead.
Water sits in the pot and never drains
The step was zero: the planter’s floor ended up level with the tray floor, so there is no downhill for the water to run. Nothing can be done after firing. Next one, check the step with a needle tool before you pull the walls.
The drains fused shut
Glaze bridged across the hole and turned to glass at cone 5½. Clear every hole after glazing, from both sides, and hold the piece up to a window to check. A blocked drain turns the planter into a very heavy vase.
It welded itself to the kiln shelf
A moving glaze pooled in the moat and ran over the lip, or glaze was left too close to the bottom edge. Come and find a member of staff before you start levering at it. Fixing fused pottery covers what is worth trying.
The lip chipped
It is the thinnest and most exposed edge on the piece, and it is at exactly the height that catches on shelves. Bevel it slightly while it is wet, never stand the pot on it, and carry the piece by the planter rather than the tray.
It tore coming off the wheel
It was wired off instead of being left on its bat. A wire has to travel under a wide thin flange and then the flange has to slide, and one or the other of those will lose. Bat, every time, no exceptions.
The plant died anyway
The pot was fine and the moat sat full for a fortnight. An attached tray asks for a little more attention than a loose saucer, not less, because nothing empties itself. If that sounds like a chore, make the moat bigger on the next one.
16 · At the wheel
At the wheel
The list to keep open on your phone
In order, from a bare bat to a cleared drain. Tap an item to tick it off. It remembers where you got to, so you can put the phone down, wash your hands, and come back to it.
In order, from a bare bat to a covered tray. Tap an item to tick it off. It remembers where you got to, so you can put the phone down, wash your hands, and come back to it.
17 · Questions
Things members ask us about these
If yours is not here, ask at the front desk. Somebody will have made the same mistake recently and will be pleased to tell you about it.
Can I just attach a saucer to a pot I already bisqued?
No. A join needs both halves to shrink together, and a bisqued pot has already done all of its shrinking while the fresh clay has all of its still to do. The new piece will crack off in the glaze firing, cleanly, and take a chunk with it. If both halves are only leather hard you are fine; if either one has been through a kiln, start again.
How big should the drainage holes be?
Three eighths of an inch cut, which finishes at roughly five sixteenths. Three of them for a four inch planter, four for a six inch, five for an eight inch. More small holes drain better than one big one and are far less likely to be plugged by a single root or a single drip of glaze.
Do I need side drains on the two-piece version?
Only if the foot ring is solid. The two-piece route lets you keep a conventional hole in the middle of the floor, but then the water has to escape sideways from under the pot, which means notching the foot ring. Solid ring plus central hole equals a sealed chamber, and that is the one arrangement on this page that does not work at all.
Should I glaze the inside of the planter?
Whichever you prefer the look of. Glazed is easier to clean. Bare is traditional, and people will tell you the wall breathes, which is true of low-fired terracotta and much less true of our stoneware at cone 5½. What is not optional is glazing the inside of the tray and keeping glaze out of the drains.
Can I leave one outside?
On a covered porch, yes. Out in the open, no, because rain fills the moat and the moat has no way to empty itself, so the plant sits in standing water for however long the weather lasts. And in a Utah winter a full moat that freezes will split the tray. Bring it in, or empty it before it gets cold.
Do I need gravel in the bottom for drainage?
No, and it actively makes things slightly worse. A layer of gravel under potting mix raises the level at which water stops draining rather than lowering it, so you end up with a wetter root zone in a smaller pot. Fill it with potting mix and let the drains do the draining.
How much water does the moat actually hold?
About eight fluid ounces on a six inch planter with a nine inch tray and a half inch step, which is roughly one proper watering. Smaller than that and you will be emptying it every single time, which is the reason most people abandon the form.
Can I make one on the slab roller instead?
Yes, and if the step is the bit you keep getting wrong it is arguably the better route, because you cut the measurement instead of judging it. Square and oval versions really only happen this way. Round every internal corner generously; corners are where slab-built trays crack.
What is the smallest one worth making?
About four inches across the planter. Below that the moat gets so shallow that a single watering overtops the step, and you have made a very pretty object that needs a sponge every day. Barbara Dunshee throws a nice small one from a pound of clay in one of the videos above, and that is close to the floor.
Where to go next
One measurement decides whether this is a planter or an ornament
Go and throw a small one
Everything else on this page is technique, and technique is learnable in an evening. The step is the part that is a decision, it happens in the first five minutes, and it cannot be revisited. Make a small one, get the half inch right, and then make the one you actually wanted.
Three pounds, a bat, and a half inch step. Get that right once and the big one is the same job with more clay. If you want the reasoning behind any of it, or the other two ways to build one, the comprehensive version at the top of this page has all of it.
Compressing the floor and rim
Why a wide flat tray floor cracks across the middle, and the thirty seconds that prevent it.
Scoring and slipping joins
The join that holds a two-piece version together, and the corner weld that does most of the work.
Cutting clean holes
Tools, timing and burrs. An entire page about putting holes in leather hard clay without wrecking it.
Trimming and turning
Foot rings, chucks and timing, for the version where you trim the planter before you attach it.
Using dipping glazes
What happens when you dip a pot that has holes in it, and how to stop glaze pooling where you do not want it.
The calculators
Shrinkage by clay body, and what the box your finished piece occupies is going to cost to glaze fire.
Which version would you like to print?
Videos come out as a labelled box with the title and channel to search for, since paper does not play them.