The Celtic Tree Calendar has thirteen months, one for each lunar month in the year, but most contemporary Celts, Wiccans and Pagans have adopted fixed dates to keep it in sync with the Gregorian calendar currently in use in the western world. Of course, it is rather doubtful that the Celts actually used this calendar but referencing it is a lovely way to honour the sacred trees of the Celts throughout the year. FYI, in Irish Gaelic, September is called “Mà Meán Fomhair” meaning “middle of harvest”.

Ogham rune Vine aka Muin
“Muin,” or Vine, is the tenth month in the Celtic calendar and celebrates the harvest and beginning of the fall. The Vine, in nature, spreads easily and entwines itself around other plants, linking them together. In our world, this represents the importance of collaboration, cooperation and mutual respect. The Vine can explore hard-to-reach places, with determination and beauty (its flowers) and the gift of its abundance (the fruit of the vine, and the vines themselves … a useful item for basketry).
There are opposing views on which plant the vine rune and month referred. Some say that it refers to the local brambles (rough prickly shrubs such as blackberry), suggesting that it was the Romans who introduced the grape vine. Others say there was grape vine imagery in artifacts from the Bronze Age Ireland (I have not yet seen that imagery). But perhaps it doesn’t matter what precisely which Vine inspired the rune or the month. Both brambles and grapes bear fruit in September, and both the fruit and the vines are harvesting, the firmer for wines and the latter for basketry.
The Vine is associated with passionate emotion and is a good time to focus on balance, as it is the month of the Autumn Equinox. Yet it is also associated with the Dark Mother goddesses, as the Wheel of the Year turns towards its end/beginning at Samhain… a time of increasing intuition and connection to deep inner knowledge and self-awareness of one’s shadows.