About 3 years ago or so, I was searching the web for organic solutions to combat pests in my rose garden and came across information on companion planting. So I started reading books on gardening and found that garlic could be planted next to rose bushes to keep the pests away.
I think for the first season we went to our local Home Depot and bought some garlic bulbs and planted them next to our rose bushes late fall. Yeah it definitely helps during growing seasons – unfortunately it won’t keep those nasty japanese beetles away though. 
If you need a different variety of garlic (that your local store/nursery doesn’t offer) and/or organic garlic you can try Territorial Seed Company.
So we have been growing garlic for almost 3 years now and you could plant them in late fall or early spring.
Depending on the time of planting those garlic bulbs will mature in summer or early fall.
You can find more information on growing garlic here.
[...] prefer doing companion planting (my blog post on companion planting here) and was able to find a couple of ice spots in between my rose [...]
[...] planting – Garlic plants & rose bushes goes together. More information at http://the8thwonder.org/2007/10/10/smell-that-garlic/ [...]
Could do with something to keep the beetles off the tomatoes.