You can now either use that plant to create a potion through Apothecary, or you can convert the plant into another seed via CTRL+right click. Grow seeds using your Miracle Grow Add-on box. Just grow each seed by itself with no additives.
Currently it is more cost effective not to purchase any of the Cultivating materials like soil and water.At 50, you get another slot at 100, a third and at 150, a fourth. At level one Cultivating, you'll only be able to Cultivate one seed at a time.First thing's first: enable the Add-on Miracle Grow Remix (press Esc -> Customize Interface -> Mods/Add-ons -> then Enable the Add-on).