The best time to plant roses depends almost entirely on your climate. First determine which USDA Hardiness Zone you live in. Speak with local rose growers. There's probably a club in your area, or simply ask experts at your local garden centers.
Keep in mind that before you plant roses, all danger of frost must be gone. If you live in an area where the winters are mild and spring comes early, you're in luck. You'll have a lot of flexibility when you can plant roses. The best time to plant roses in this kind of warm climate is in the late fall, or early spring.
If your roses are bare root, you can plant them during the dormant season in your area, as long as the ground isn't frozen or waterlogged, and the danger of frost has past.
January and February are great planting months in warmer climates. If you live in the Midwest or Northeast, you'll likely not be able to plant until March at the earliest. In some areas, you may not be able to plant roses until May.
Watch the Garden Centers
Here's another way to tell when the best time to plant roses in your area: when they begin to show up at your local garden center. This is because live flower shipments need to closely coincide with local planting times; otherwise the retailers won't be able to sell them. Be sure to plant your rose bushes shortly after purchasing them and mulch them in case of a late frost.
You should avoid planting roses when it's too windy. Bare root roses should be planted before they leaf out. If you plant these during colder weather, be sure to insulate them well with straw, plastic cones, and protective mulch.