I had to wait till the last evening of summer between midnight and 6am into the fall
1. Facing the bench by the waterfall opposite the Nightly Mushrooms which won't harvest till Winter... Listed as Strange Mushrooms you don't know what they're till you pick them.
2. There are 3 patches of Strange Mushrooms just in front of the snail path and finally.
3. Another Strange Mushrooms patch in front of the Gazebo.
1 patch turned out to be Charming Mushrooms, but I haven't checked the all the other ones yet.