i wish everyone included a copy of their spreadsheet when asking a question as it makes it so simple to answer. i will repeat what LadyCFII said above, except I will use more words and do it without a beautiful avatar.
Since you do not have any plants to the left or above your desired plant, you cannot breed it with the plants you have. so your two choices are to either buy the plant you want (or a close relative of it) from the store (pretty much anything that is above and to the left of the desired plant will of course help you), or mutate something you have into something you want. i would pick a plant close to the plant you want to reduce how many mutations you need to do. in this case..
mutate your bluestar astera twice to get a nox orchid.your chance of mutating the bluestar on the first try to either a nox astera (25%) or a bluestar orchid (25%) is 50%. Your chance of then mutating that plant on your next mutation to the nox orchid is 25%. Thus, your chance of two mutations in a row producing what you need is 12.5% (1 in 8).
there is a way of improving your odds from 12.5% to
100%. Save your game, attempt the mutation, then restore your game if your mutation went the wrong way. don't know how to save/restore you game? Check
HERE.
(some would argue this is a form of cheating, some would argue it is not, and some would rather have a tunafish sandwich, which is what I am off to make
)