Here is every ingredient and item for every spell, potion, and command and where to find them all. If you see anything that might be missing, please tell me. I have also included the locations of cottages and gardens where you can find these ingredients.

Locations of Cottages and Gardens

      Some ingredients are measured in different amounts. Here is a guide of some of those amounts. Since there aren't measuring cups and such in the game, this is only a rough guide. In the game, it's hard to be exact. (Ex: Instead of 100/100ths while drinking a bottle, there are actually about 65/100ths.)

Ground Ingredients: 50 Pinches = 1 Handful
Stalks: 50 Stalks = 1 Handful

Liquids (and Honey):

1 Gallon = 4 Quarts 1 Quart = 2 Pints 1 Pint = 2.5 Cups 1 Cup = 24 Ounces 1 Ounces = 4 Dollops 1 Dollop = 10 Drops

Consumption:

1/100 = Tablespoon 1/50 = Sip 1/20 = Taste

Ingredient/Item:	Spells, Potions, Commands Used In:	Places Found:
Apple	~ Goody Whemper's Apple Divination (unpealed) ~ Mother Harblist's Fruity Flyer	~ Upstairs of Granny's in paper bag ~ Picked from the apple tree in the Temple of the Listening Monks ~ Bought in Various Places
Apple, bright red (Poisoned)	~ Tempt	~ Grocer on Fast Lane in Ankh-Morpork ~ Gingerbread House in Skund Forest
Basil	~ Poison Antidote Potion	~ Gardens in Scrogden ~ Garden on Gate Ave., Sum Bing
Basket	~ Tempt	~ Bought in Various Places ~ Cellar at Granny's ~ Gingerbread House in Skund Forest
Borage	~ Energy Potion	~ Gardens in Scrogden
Candle	~ Mama Blackwing's Potent Preserver	~ On the Ledge in Granny's Privy ~ On the Dresser Shelf in Granny's Kitchen ~ Bought in Various Places
Carrots	~ Anti-Blind Tea (ground)	~ Gardens in Scrogden ~ Bought in Various Places
Circle Items	~ Circle	~ Bought in Magic Shop on Dione Street, AM ~ Bought in Hidden Shelter on Ming Lane, Pong Ping ~ Majjik stall in Lancre Town ~ Occult jewellery stall in The Plaza of Broken Moons, AM
Club Badges	~ Gammer Tumult's Amalgamator	~ Various Club Rooms
Coffee	~ Energy Potion	~ Bought in Various Places
Comfrey	~ Healing Tea (ground)	~ W of privy at Granny's ~ Gardens in Scrogden ~ Gennie's in Ankh-Morpork ~ Garden in Mad Stoat ~ Garden in Sto Lat ~ Bought in Hilta's Stall in Ohulan Cutash ~ Shelf in CWC Witches' Hut ~ Hidden Garbage Heap on Ming Lane, Pong Ping ~ Garden on Gate Ave., Sum Bing
Duck's Feather	~ Granny Lipintense's Layer of Lard	~ Pond in Dinky ("chase" ducks) ~ There are many ducks and ducklings around CWC (mainly near the river) that you can kill for their feathers.
Eel Skin	~ Granny Lipintense's Layer of Lard	~ Pond in Dinky ("catch" and "get" skin from corpse with sharp object) ~ Blue Moon Park in Bes Pelargic
Eyebright	~ Anti-Blind Tea (ground)	~ Gardens in Scrogden ~ Garden on Gate Ave., Sum Bing
Fennel Seeds	~ Poison Antidote Potion (ground)	~ Gardens in Scrogden ~ Garden on Gate Ave., Sum Bing
Frog (Speckled)	~ Mama Blackwing's Potent Preserver	~ Scullery at Granny's (Search under bed in Granny's bedroom (chamber pot). Get stockings from drawers in bedroom. Get tea strainer from drawers in kitchen and repair strainer with stockings. Close window in scullery, fish frog from well, then get frog from chamber pot.)
Floppy Madmen Mushrooms	~ Focus Tea (ground)	~ W & N of Privy at Granny's ~ Hidden Shelter on Ming Lane, Pong Ping
Fruit	~ Tempt ~ Mother Harblist's Fruity Flyer (To feed your bat.)	~ Bought in Various Places ~ Melon patches west of KLK
Garlic	~ Cold Cure Potion (ground)	~ Granny's Herb Garden in Bad Ass ~ Gardens in Scrogden ~ Garden in Mad Stoat ~ Garden in Sto Lat ~ Garlic fields west of KLK
Ginger	~ Energy Potion	~ Gardens in Scrogden
Goat Pellet	~ Gammer Shorga's Helpful Undergrowth	~ 2W of Granny's Kitchen, enchant ~ Outside the hidden shelter on Ming Lane, Pong Ping
Hagstone (Large Round Stone)	~ Tricks	~ "Search" at the river Scrogden ~ "Search" at the willow tree at Granny's ~ "Search" along the riverwalk in Knot-Lip-Khin ~ "Search" the riverbed of the river in Bes Pelargic ~ Bought in Hilta's Stall in OC ~ Bought in Hidden Shelter on Ming Lane, Pong Ping ~ Majjik stall in Lancre Town
Hagstone (Small Round Stone)	~ Imbue, Educe	~ "Search" at the sign by Granny's
Honey	~ Mother Feelbright's Busy Bees (dollop) ~ Cold Cure Potion	~ 3W of Granny's Kitchen (Get a honeycomb from a bee hive and shake the honeycomb into a jar or bottle for honey.) ~ Magrat's Cottage in Mad Stoat ~ Mum's Cottage in Sto Lat ~ Confetti Lane, Pong Ping District in Bes Pelargic, CWC ~ Majjik stall in Lancre Town ~ Hilta's Stall in OC
Household Items (small knife, rolling pin, frying pan, flatiron, cleaver, etc.)	~ Grammer Scorbic's Household Guard	~ Bought in Utensil Shop in Bad Ass ~ Bought in Ankh-Morpork ~ Bought in Utensil Shop in Bes Pelargic
Ink	~ Gaze	~ Bought in Various Places
Ivy Seed	~ Gammer Shorga's Helpful Undergrowth	~ On the roof of Granny's Cottage ~ Along the wall in Hong Fa/Golden District of Bes Pelargic
Ladder	~ To get on roof of Granny's Cottage	~ West of Privy at Granny's (West of privy at Granny's, get undergrowth. Lead the nanny goat with undergrowth to privy. She'll eat the undergrowth and expose the ladder. Get the ladder and drop it by the cottage to climb to the roof.)
Magick Crystals	~ Imbue	~ Bought in Hilta's Stall in Ohulan Cutash ~ "Search" the shelf in Hilta's Workroom ~ Bought in the hidden shelter on Ming Lane, Pong Ping
Owl Feather	~ Intelligence Potion	~ Gardens in Scrogden (Fix swing in Gardens in Scrogden (ask Hughoc), then swing and get feather from tree.) ~ Owl in Granny's Scullary
Parsley	~ Breath Freshener Potion (ground)	~ Gardens in Scrogden ~ Garden on Gate Ave., Sum Bing
Sage	~ Intelligence Potion (ground)	~ Gardens in Scrogden ~ Garden on Gate Ave., Sum Bing
Scumble	~ Hedgehog Song ~ "Bribe" Nanny for Hedgehog command	~ Nanny's "Secret" Stash (upstair in Nanny Cottage, Lancre Town) ~ Bought at Various Places
Smelly Seed	~ Gammer Shorga's Helpful Undergrowth	~ To make a smelly seed, enchant a goat pellet and then put a ivy seed in the pellet. If done correctly, the pellet should explode after a time, leaving behind a smelly seed.
Sugar, lump/cube	~ Mama Kolydina's Instant Infestation	~ Bought at Various Places ~ Kitchens ~ Pantries
Spider (Of the Small Variety)	~ Poison Antidote Potion (ground)	~ Granny's kitchen (Enter the chimney to "catch" the spiders.) ~ Outhouse near Gate Ave., Sum Bing
Vorpal Bunny Eyes	~ Anti-Blind Tea	~ Not in game yet. ~ Will probably be at the paddocks in the gardens at Scrogden.
Willow Withe	~ Mother Brynda's Call of Gravity	~ E of sign at Granny's (Cut from tree with something sharp.)
Yarrow	~ Mother Twinter's Yarrow Enchantment ~ Healing Tea (ground)	~ W of Privy at Granny's ~ Gennie's in Ankh-Morpork ~ Garden in Mad Stoat ~ Garden in Sto Lat ~ Bought in Hilta's Stall in Ohulan Cutash ~ Shelf in CWC Witches' Hut ~ Hidden Garbage Heap on Ming Lane, Pong Ping

Locations of Cottages and Gardens

Ankh-Morpork
Gennie Applebottom's Cottage: From the Guild Carriage stop on Holofemes, 2 west, northwest, north, northwest, 2 west, northest.
Gennie Applebottom's Conservator: West of Gennie's sitting room.
The Temple of Small Gods Garden: East end of the Temple near Florette on Small Gods Street.

Bad Ass
Granny's Cottage (Kitchen): From carriage stop in Bad Ass, 2 west, southwest, north, 2 northwest, east, north, east, north, northwest, south.
Granny's Herb Patch: West of the Privy.
Granny's Mushroom Patch: North of the Herb Patch.
Granny's Cellar: North and down from Nanny.
Granny's Bee Hives: West from outside the back door.

Scrodgen
Ethel's Cottage: Southwest of the shadoof.
Gardens: Northwest, north, 2 west, north of the shadoof.

Mad Stoat
Magrat's Cottage: South, east, northeast from the carriage stop.
Magrat's Garden: East of the entrance to her cottage.

Sto Lat
Mum Blithesome's Cottage: From the crossroads of Grave's Hope and High Street, 3 east and north.
Mum Blithesome's Garden: West from downstairs of Mum's cottage.

Slice
Millie Hopgood's Cottage: North of Millie's garden.
Millie Hopgood's Garden: From the carriage stop in Bad Ass, southeast, south, southeast, east, southeast, south, southeast, east, southeast, 2 northeast, 2 east, and north.

Counterweight Continent
Witches' Hut: From Confiscated Items Shop in Pong Ping District, west, 3 north, southeast, northeast, southeast, 2 northeast, 2 northwest, 2 southwest, northwest, northeast, north.