Flowerpots were introduced in Patch 3.3. They allow you to grow the same crops indoors as you can in an outdoor garden. Flowerpots can also be used to grow different color flowers including Brightlily, Dahlia, Daisy, Oldrose, Shroud Cherry, Tulip and Viola's which can be displayed in vases once harvested. Flowerpots cannot be used for crossbreeding.
Flowerpots, vases, seeds/saplings and pomace can be purchased from the Material Supplier in each Housing District. Once you have your flowerpot placed in your residence you can begin growing some flowers! This guide will focus on obtaining different color Oldrose flowers. Keep in mind you can follow the same steps for all other flowers which have been introduced in recent patches.
There are ten different colors available. Red, Blue, Yellow, Orange, Purple, Green, Black, White and Rainbow/Pink. Feeding a certain color of pomace will change the color of the harvested flower. For example, to grow an orange Oldrose you will need to feed 1 Red Pomace and 1 Yellow Pomace total. The first six colors only require you to mix one or two pomaces whereas the last four (Black, White and Rainbow/Pink) require you to feed at least three different colors and let chance take its course.
Be sure to check out the Flowerpot Gallery for a screenshot of every flower's color options.
The default color for every flower is Red except for Viola / Hyacinth / Cosmos (Purple) and Daisy (Yellow). You can see this by selecting the plant once it has been planted. Once you have your desired color you can feed regular fertilizer (Fishmeal) to reduce grow time without changing the color again. Cuttings will take 24 hours to grow from seed to harvest without fertilizer.
After you feed 1 Pomace of each color you will receive the "{Default color} flower / Unusual Shade" message. From here you can feed again to change the colors as you wish but will also have a random chance to receive a white, black or rainbow/pink flower.
The type of soil used will also affect your yield. Thanalan soil only gives you one bouquet while Shroud can yield up to two. La Noscean can yield an HQ bouquet but there's really no reason to have one. You can track my personal harvests via the Gardening Spreadsheet.
Below is an overview for how to change colors using an Oldrose. Adjust accordingly using the other flowers. The color pink for Cherry Blossoms replaces the rainbow color.
Desired Oldrose Color Fertilizer Needed Red Oldrose Blue Oldrose Blue x1 Yellow Oldrose Yellow x1 Orange Oldrose Red x1 Yellow x1 Purple Oldrose Red x1 Blue x1 Green Oldrose Blue x1 Yellow x1 Black Oldrose Red x1 Blue x1 Yellow x1 + RNG White Oldrose Red x1 Blue x1 Yellow x1 + RNG Rainbow Oldrose Red x1 Blue x1 Yellow x1 + RNG