Leading '-' or '~' characters are tick specification characters and will not appear on the labels. They just specify the the tick style to be associated with the labels. If you want have a label that actually begins these characters, add '\' as the first character as the escape character.

One common issue is that there may be too many labels on the axis. You can remove some labels by replacing them with empty strings. If you want to remove the label text but leave a major tick, use a " " as the label text.