Lammas/Lughnasadh/Freyfaxi is the holiday celebrated on or around August 1st in the Wheel of the Year, and can have many different meanings depending on the particular culture your variety of Paganism celebrates (hence the many different names). Generally speaking, this is the first of the harvest festivals in the Wheel of the Year and is the celebration of the grain harvest.
Lammas is the Anglo-Saxon celebration of “loaf-mass”, when the first loaf of bread made from the new year’s wheat is blessed, and then used for magic, usually to protect the rest of the grain crop. In the Anglo-Saxon chronicle it is referred to as the “Feast of first fruits”, which is mirrored in the modern Pagan celebrations of this time as the first harvest. This time also marks the end of the hay harvest, and the beginning of the harvest of grains.
Lughnasadh is the Celtic celebration of the first harvest, as well as the commemoration of the god Lugh for his foster mother Tailtiu, who died after clearing the plains of Ireland for agriculture (usually celebrated with games and sport and feasting). This was one of the Celtic “Fire festivals” and was often celebrated with bonfires and the visiting of holy wells. Ashes from Lughnasadh bonfires would be used to bless fields and livestock (A tradition that continues in Christianized Ireland, where priests frequently bless fields on this day). This was also traditionally a time of handfasting.
Freyfaxi may be a type of Norse festival of sacrificing horses to Freyr, who is the God of the harvest cycle in that culture. Unfortunately it seems to be named for a horse who was dedicated to Frey, but was stolen by a traitor priest who then defiled Frey’s holy stead, so I’m not really sure why there is a celebration in honor of it. (However, it is possible that there were horses sacrificed to Frey, it’s more the name that is concerning). In modern times it is seen as a sort of parallel to Lammas (which comes out of the Anglo-Saxon tradition). Some modern Norse traditions celebrate this time as one of community and sport, as it was the time of the annual All-Thing in late July and early August.
In modern Paganism, this is the time of the sacrifice of the Grain God, who lays down his life (as the grain is the “sacrifice”) only to rise again with the next year. This is commonly retold in the story of John Barleycorn, who dies and is reborn the next year. Many traditions practice offering up sacrifices in order to continue the turning of the seasons, in a mirror of the sacrifice of the God, who must die for the fields to be replenished the next year. The Goddess is pregnant at this time with the God who will be born again at Yule, to be sacrificed at Lammas the next year. Often this is celebrated with sacrifices of bread and other grains, and magic that centers around reaping the fruits of hard labors. Similarly to the Anglo-Saxon tradition, a loaf of bread is often baked and then ritually “sacrificed” to represent the sacrifice of the Grain God.
I usually celebrate this time of year by clearing out my garden in preparation for the fall planting season. It feels appropriate to be cutting down the old plants and starting the plot anew, with offerings of compost and manure. It’s still too hot to plant anything yet, but I try to start the “sacrifice” of the old plants that get tilled into the earth to renew the garden and bless the upcoming harvest (that will be ready in November or so). I also try to make freshly baked bread (usually cornbread, since I can’t eat gluten, so I don’t keep wheat in the house) to add to the sacrifices that are made at this time of year. This year, since I have just discovered the tradition of using that first, blessed loaf as a magical ward, I’ll be baking the bread, giving it as an offering, and then placing quarters of the loaf around the outside of my house.