I don't see why not, but I may be wrong. One thing, mint is best grown in containers or with a sunken barrier around it, as it can very invasive.

You don't say where you live which would be helpful. If your area is mild enough for rosemary to overwinter outdoors then it will need quite a big space to grow. Think in terms of giving it 3 - 4 feet width. If you pus your sage too close the rosemary will over shadow and eventually overgrow it.

The advice on mint from BioTomato is good. Mint is best kept separate because it spreads. It also like more moisture than the other two.

thank you . i live in a pretty mild area so we should be ok. how big should i make the barrier 4 the mint?

I would probably not plant the mint with the rosemary and sage. Those two like it drier with more drainage than the mint does.

Many people like to keep mint in pots to limit the spread. I don't have that much problem with mint spread so I plant it directly in the ground.

FataMorgana