Oasis Springs - Across the street from Rattlesnake Juice in the dirt area. Also at end of road by Museum.
Mushroom
Common
$4-$10
24h
Seed Packet
Parsley
Common
$5-$13
24h
Seed Packet
Plantain
Common
$16-$40
72h
Seed Packet
Sage
Common
$5-$8
24h
Oasis Springs, end of road by Museum. Also across from Sandtrap Flat in the garden area.
Snapdragon
Common
$13-$33
36h
Willow Creek, Garden Essence Home (BFF Household)
Spinach
Common
$3-$8
24h
Seed Packet
Cherry
Uncommon
$15-$39
60h
Oasis Springs - Behind the Park by Springscape.
Lily
Uncommon
$18-45
36h
Willow Creek Park, also in front of Oakenstead
Onion
Uncommon
$14-35
48h
Willow Creek, Rendle Rose (House)
Pear
Uncommon
$14-35
60h
Willow Creek Park, also behind Umbridge Manor (Mansion)
Potato
Uncommon
$10-$25
24h
Willow Creek, Garden Essence Home (BFF Household)
Rose
Uncommon
$18-$45
48h
Willow Creek, Behind Umbridge Manor (Mansion)
Strawberry
Uncommon
$8-$20
24h
Willow Creek, Garden Essence Home (BFF Household)
Tomato
Uncommon
$12-$30
24h
Oasis Springs, up the road from Slipshod Mesquite (the home that looks like a trailer) are planter boxes. There you will find Tomato and some other plants.
Tulip
Uncommon
$11-$28
36h
Oasis Springs, near the abandoned mine down the hill behind the Landgraab Mansion.
Blackberry
Rare
$55-$138
96h
Oasis Springs - near the dirt path beside the big Park.
Cow Berry
Rare
N/A
24h
Cow Plant berries have been found while Fishing at the glimmering stream with a cave in Oasis Springs' Big Park, as well as Sylvan Glade's larger body of water. You can also get a Cowplant by using Take Cutting from a Snapdragon and Grafting it onto Dragonfruit, but again, Grafting new types of plants is broken at the moment. These may also be found while on missions in the Rocket Ship via the Rocket Science Skill. More on Cow Plants Below.
Orchid
Rare
$22-$58
36h
This was found by myself and another after completing the Space Rock collection from the Rocket Science Skill.
Pomegranate
Rare
$18-$45
72h
These have been found while Fishing in Magnolia Blossom Park, Willow Creek. I caught one in the central pond where you can also look for frogs while fishing without bait. I suspect you can get one by grafting Cherry with Apple, but the interaction will not go through.
Trash Fruit
Rare
$4-$10
24h
Have your Sim take out the trash, but cancel the interaction. Let this trash sit in your yard (it can be moved in buy mode), and it'll become one very unhappy trash plant. Water it fast, and one day you'll have your very own Perfect Trash Plant.
U.F.O.
Rare
$120-$300
112h
These evidently don't need watered, but do need weeded. Unidentified Fruit Object is what you harvest, but the plant is actually named Intergalactic Growth Pod. U.F.O. Fruit has been found while on adventure in the Rocket Ship. I got one while an Astronaut in an encounter with the Green Man (like Yoda). I took the weapon and defeated the Nega-Sim and got a Cowplant Berry along with an U.F.O. as a reward!