Instructions
Bird of Paradise
Talk to Seedos until he gives you a Bird of Paradise seed.
Go to the Costolot and you will find the Bird of Paradise seeds are now available. Buy these seeds for 55 coins each. Get as many as will fit into a new garden.
Water the plants and apply Ivor's special mix fertilizer three times. The seeds will grow into a plant worth 1400 coins each so sell them all for a large cash injection.
Flower Heads
Purchase a Venus Pinata Trap from the Costolot.
Put it right in the center of your garden. Wait for it to grow, and when it does, all of your pinatas will be drawn to it, knocking down the flower heads in the process.
Sell the flower heads before the pinatas eat them. This plant produces many flower heads and each one can be sold for 360 coins.
Hit Seedos a few times with a shovel if you want to do this trick with poison ivy. Seedos will give you weed seeds. Sell the flower heads when the weed dies.
Chili
Buy ten chili seeds at the general store, since ten is the most you can plant.
Plant them in groups of four with the remaining two seeds also grouped together.
Use the red fertilizer on them. Since the seed are grouped together you won't need to use as much. Repeat the fertilization three times.
Sell the plants for 400 coins each.
Taffy Transformation
Move two taffies into a torch to set them on fire.
Use a watering can to put out the flames and your taffies will transform into Reddhotts that you can sell for $2,100 each.
Romance the two Reddhotts and sell the pinata babies they have for even more money.