With how vast the Lands Between is in Elden Ring, it can be incredibly easy to lose sight of your progress or what direction you're going in the game, putting you in front of an incredibly difficult boss early on or leaving you with under-upgraded assets.
How to upgrade your Spirit Summons in 'Elden Ring.'
If you want to upgrade your Spirit Summons in the game, you'll first have to obtain the items necessary for the upgrade. To do this, you'll want to find either Grave Glovewort or Ghost Glovewort. Grave Glovewort has a long green stem with silver petals, while Ghost Glovewort looks similar, only it glows, making it easier to spot in the wild.
These items are hidden in various places around the map — usually in dungeons or dropped by various bosses. That being said, you can also get them by purchasing them from various merchants located around the map or by completing different quests for NPCs. If you aren't sure where to find a merchant, now the Elden Ring map will show you the current location of all of the in-game merchants you've already found.
You'll also have to help Roderika, who can be located at Stormhill Shack. Speak with her until you've gone through all of her dialogue. She'll ask for your help obtaining Chrysalid’s Memento, which is in a pile of corpses near the Grafted Scion mini-boss in Stormveil Castle. You'll want to be sure to bring this back to her before you defeat Godrick the Grafted, or she won't be able to help you.
By helping her, she'll gift you the Jellyfish summon — one of the more powerful Spirit Summons in the game. Roderika will then move to the Roundtable Hold. After you've spoken with both her and Hewg, she'll set up a shop across from the other NPC. Here you can trade either Grave Glovewort or Ghost Glovewort to upgrade your Spirit Summons, depending on which one you're looking to upgrade.