That is the diameter of a vole hole, but I have also trapped mice near such holes. You can try mousetraps baited with peanut butter, preferably covered with something to discourage other critters from springing them. These will catch some voles. Look for runways entering or connecting the holes. I think it is worthwhile planting new roses in wire cages. A ring of hardware cloth 11" deep and 1" above the surface may be enough.

Wilting would be a sign of vole damage and would call for lifting the plant immediately and replanting with protection. Don't trust any kind of repellent

Thank you, Michael. I'll go ahead and lift and replant to protect it today while we have favorable weather.
Kate

A member of our rose society reported success with sticking a hose in the holes and letting it run for awhile (don't know exactly how long) until the runs were flooded out.

Since you only said there was a hole and nothing about runs I would venture to say you need to watch it before jumping to conclusions.

I had such a hole near a rose once like that which I promptly colapsed each day. That is until I discovered it was from a toad backing up into the moist soil.

Point is...organic methods mean we observe first and then evaluate if helpful or harmful before we take ANY action.

You may find you have a toad "on duty" or submerged for a siesta!