Which Ice or Grass type Pokémon has the least weaknesses?

Question

Ice and Grass types have a lot of weaknesses. They're known to be terrible types. So, which Ice type has the least weaknesses? And which Grass type as well? Second typing is also included.

Answer 1

With the help of an ability, the winner would be Mega Venusaur with 2 weaknesses of Flying and Psychic.

Without an ability, they would be the Ferroseed line and Kartana (Grass/Steel) with 2 weaknesses of Fire (4x) and Fighting.

Also, they would be the Alolan Sandshrew line (Ice/Steel) with 3 weaknesses of Fire (4x), Fighting (4x), and Ground.

If you want triple-types, Grass/Steel/Fairy with 1 weakness to Fire (4x) and Ice/Grass/Steel with 2 weaknesses to Fire (8x), and Fighting (4x).

Source: knowledge of Dual-type Chart and This (especially for the triple-types)

Comments

Don't forget, Rotom-F also only has 3 weaknesses (Fighting, Rock, Fire) thanks to its ability: Levitate.

---

Wrong, It's Ice and Rock weaknesses for Fan Rotom. You're thinking of Frost Rotom., which would overwise be correct.

Answer 2

Ice Type: Funnily, Ice/Steel has the smallest amount of weaknesses, but they have 4× weakness to two types, Fighting and Fire.
Alolan Sandshrew and Alolan Sandslash are Ice/Steel Pokemon
They have three weakness.
Grass Type: Grass/Steel has the lowest amount of weaknesses, but they have 4× weakness to Fire and two 2× weaknesses.
Kartana, Ferroseed, and Ferrothorn are Grass/Steel Pokemon.