I have a rosemary plant that is almost the size of a shrub. I have brought it indoors for the last three winters. It is getting too big and I wondered if I could winter it outdoors in Minnesota if I give it some additional protection?
Rosemary is winter hardy in zones 8 and higher. It will not survive temperatures below 10 degrees. That excludes growing it outdoors year round in Minnesota. Someone from Michigan Fox Hill Farm's has had occasional luck overwintering the hardier variety Rosmarinus officinalis alba outdoors. Keep in mind, the weather tends to be milder there. Try finding a greenhouse or friend with an atrium to provide space for overwintering this large plant. Or take cuttings and start new plants that will be smaller and more manageable than your large shrub. Then donate the parent plant to a nursing home or other care facility that has good indoor growing space and uses plants as part of their activities program.