This is going to be rough up north where I am, too much snow.
1. Touch snow
2. See the sun while outdoors.
3. Say hi to someone in person.
4. Text a friend or family member.
5. Touch a tree.
I think touch a tree would be the most direct substitution. Something to be said for a social substitution too though, but it probably doesn't match the initial intent of touching grass.
Then again maybe that would be a good thing.
You'll never use social media again.
Touch snow.