I'm trying to protect my hostas from voles by planting them in 3 gallon plastic containers before placing them in the ground. I have four questions and would appreciate help from anyone who has to constantly deal with voles.

1.) I've covered the bottom of the pots with sharp edged gravel. Should I also drill holes in the sides/bottoms of the containers as well?

2.) I purchased some crushed oyster shells. Should this be mixed throughout the soil or only placed as the top layer to protect the plant?

3.) When hostas are planted in the ground in containers, do they require daily watering?

4.) I mulch with shredded bark to help control the weeds in my hosta beds. I've read that this attracts voles as well. Should I discontinue this practice?

Thank you.