And really I did not take adequate notes on which flowers bloom when.
The cycles of which wildflowers mark which months -- more or less, allowing for weather variations -- are one of those clues to let the reader into how much time is passing. But if the readers are aware of it, they are also aware that the refinements are somewhat more subtle than spring flowers, summer flowers, and fall flowers. The only real evasion is to have roses, violets, snowdrops, asters, and all blooming in hearty indifference to the seasons and let the POV character notice that.
Plus, of course, the question of what flowers should bloom in a pseudo-medieval setting. If it were historical, there would be a lot more constraints. In theory. Writers often pepper the autumnal English side with goldenrod -- American flower -- or put in rhododendron hedges prior to its Victorian introduction, or have yellow roses in a medieval garden when the first yellow roses that thrived in Europe were breed from stocks brought by Napoleon for the benefit of Josephine's rose garden and breeding (famous enough that the English went to protect the stocks).
Invented folk names. Probably the safest route. The more conspicuous flowers, roses and violets and lilies, I may have to research. Or remember.