If you are looking to evolve Galarian Slowpoke into Galarian Slowbro in Pokémon Sword and Pokémon Shield, then you will need to start collecting Galarica Twigs while playing the Isle of Armor DLC.
These twigs are from a species of tree called Galarica, which grow in certain areas around the Galar region. You will be able to collect your first soon after you exit Armor Station, with the tease that they are “a material for an accessory for a certain Pokémon.”
The bottom line here is that you will need the Pokémon Sword Expansion Pass or Pokémon Shield Expansion Pass to evolve Galarian Slowpoke, as, so far, you can only find the Galarica Twigs on the Isle of Armor.
You will need to collect eight Galarica Twigs, which can normally be found as a sparkling item lying on the ground next to a Galarica tree. Simply keep an eye out for them as you play the Isle of Armor content to save you some time, but it shouldn’t take too much effort.
Once you have collected eight Galarica Twigs, from the Armor Station in the Fields of Honor you need to travel across the Workout Sea to the southeast where you will soon reach the island where you need to go (see the screenshot below).
Here you will meet a female NPC who explains: “If you weave together Galarica Twigs, you can make a bracelet.” If you give her eight Galarica Twigs, she will kindly weave them into a Galarica Cuff for you.
The Galarica Cuff item description will then help to point you in the right direction: “A cuff made from woven-together Galarica Twigs. Giving it to a Galarian Slowpoke makes the Pokémon very happy.”
This is a single-use evolutionary item, and once you use the item on a Galarian Slowpoke it will evolve into a Galarian Slowbro.
It’s important to add that there is no way to evolve a Galarian Slowpoke into a Galarian Slowking yet, as we will have to wait until The Crown Tundra content releases in Autumn.
Pokémon Sword and Pokémon Shield are now available exclusively for Nintendo Switch worldwide.