A common strategy with this is playing a Sunflower on the first turn and if it isn't destroyed, play Mixed Nuts on the same lane as the Sunflower to activate their ability.
Because they are in the nut tribe, Smackadamia and Mirror-Nut can benefit them. However, only Wall-Knight can primarily use this combo. Wall-Knight can also play them behind bulky plants like Pea-Nut or Wall-Nut to create a simple, yet effective way of absorbing a lot of damage while doing a lot of damage as well.
However, note that Team-Up plants are a resource by themselves and shouldn't be mindlessly wasted. Therefore, do not solely rely on Mixed Nuts and play them only if they do not interfere with your main strategy.
If you're facing a Beastly hero, watch out for Squirrel Herder due to their nut tribe.
Against[]
If Mixed Nuts are unboosted, use Rolling Stone. If they are boosted, use Rocket Science. Deadly zombies and Locust Swarm are able to destroy them regardless of strength. Strikethrough zombies also help, although most zombies with said trait can't destroy them in one attack and will be destroyed themselves.
If a Sunflower is played on the first turn, then there is a high chance Mixed Nuts will be played next, so removing any Sunflowers is also important. Using Tennis Champ for Mixed Nuts and Bungee Plumber for Sunflower is one way to counter this combo on turn 2, though Tennis Champ can be destroyed before the "Fight!" phase.
Another way is by using Squirrel Herder and is a much more efficient way of doing so. Pied Piper can reduce Mixed Nuts' stats and destroy Sunflower, making him another good choice. Keep in mind that Wall-Knight and Rose can target the 2 afformentioned zombies with Grave Buster and Grave Mistake respectively.