I bought three herbs -- Sage, Oregano and Thyme -- from a grocery store each at a height of roughly 3-5 inches. I'd like to plant them in the same pot. Will they grow well together?
This article suggests they do.
They can be grown nearby one another, they prefer the same conditions, but in a pot, the three together will quickly outgrow the container. Sage is a shrub that can get 2/3 feet wide by a couple of feet or more high; oregano spreads quite rapidly sideways and takes up a lot of room eventually; it makes quite a good groundcover in the border in a sunny spot, and usually needs digging out and splitting after a couple of years to control its spread. You've not mentioned which variety of Thyme - some just creep and spread sideways and don't get higher than 6 inches, others form a small to medium sized shrub,so its not whether they will upset one another if grown together,but more an issue of space over a year or so.