Offering to Yggdrasil isn’t something that heathens normally do; in fact, I’ve hardly ever heard of anyone making offerings to Yggdrasil. I get the impression that it isn’t an entity (and it is certainly a living, breathing entity unto itself) that requires a lot of offerings. Some deities in our tradition don’t seem to be big on offerings, such as the Norns, although sometimes it truly is prudent to give Them offerings, such as when you request something of Them or They are teaching you something. They are incredibly important, no doubt, but still fairly distant from humanity and individuals who inhabit the Nine Worlds. They won’t refuse offerings even as a general honor, however. I can never see how an offering wouldn’t be well-received by any deity as long as it is given in the right spirit. However, the Norns don’t seem to ask for as many offerings as the deities who are closer to us, such as Odin, Freya, Thor, etc. I feel that Yggdrasil is the same. It is absolutely necessary for our existence, such as that of the Norns, but it’s not exactly barging into people’s lives, asking for devotional work, requiring offerings, and all the things that our deities who are more personal do. I get from UPG that the best way to honor Yggdrasil is to honor Midgard and the other worlds, keep the Earth clean and healthy, and don’t take more than you need. Yggdrasil is a tree, and trees are, well, practical, you could say. Water it, maintain it, feed it once in a while but by and large it takes care of itself and the things that inhabit it.
However, I do get the feeling that certain offerings given once in a while do delight Yggdrasil outside of taking care of Midgard. Pure water, of course, I think is the best and what you can give it the most. Yggdrasil’s waters are holy, and are the source of life for all beings in the Nine Worlds (except maybe the fire giants? No clue. There are so many mysteries). Yggdrasil’s waters run through all of our bodies in Midgard and I suspect without, as these waters are also spiritual and not just physical. They contain all memories, as in the great Wells at its roots, and we are like the leaves, offshoots of this great living wellspring. Pure water given in gratitude will be very well-received by this great entity.
This is also UPG, but a customary thing I’ve developed in giving my offerings is that if I pour any liquid offering to the Gods, spirits, and ancestors outside by the tree that grows next to my apartment, I will often flick a few drops on the tree and say “And for the tree.” It’s not only for the tree in front of me, but also for Yggdrasil. I strongly believe that any tree in our world, so long as it’s willing, can serve as a proxy for the World Tree. All trees are microcosms of the macrocosm Yggdrasil, and so we can have any tree in our world help us journey to and from Yggdrasil. Because of the relationship I have with the tree outside, it’s helped me to journey, where I felt thrust upon it and in my mind’s eye I was climbing the trunk of Yggdrasil. It was almost like pathwalking, except I wasn’t actually walking. As a holy proxy, any offerings you give to an individual tree can go to Yggdrasil if you specify. It’s like Yggdrasil is every tree’s great-great-great granddaddy, and all trees know this.
I also think that scents from wood or resins are also excellent offerings for Yggdrasil, especially if you want to invoke its wisdom. Incense and oils from things such as sandalwood, cedar, dragon’s blood, myrrh, copal, etc. would all be incredibly apropos. I’m pretty sure copal was offered to the World Tree of the Maya as well as to many other Mesoamerican Gods, as it comes from a tree… so logic follows that Yggdrasil would appreciate this, especially in a ceremony in its honor.
Of course, you also have offerings such as fertilizer and compost for trees, which I’m sure Yggdrasil would take as a service offering. Planting trees themselves would be an excellent service offering to Yggdrasil as well as Jord and Nerthus. I don’t think Yggdrasil cares about elaborate ceremonies or offerings, but I feel we should acknowledge its presence in all of our lives. It’s our literal cosmic backbone, and should be honored as such. Its waters give us life and cleanse us. Of course, they kill us too, but that’s another topic… 😉
Hail Yggdrasil. Hail the life you give us. Thank you for nourishing us and for holding us up. Hail!