I like to plant new bare root rosebushes in the very early Spring even if the temps still take some cold dips. I just mound the dirt up around them a good 6 inches up onto the canes and then pull that mounded dirt back once the warmer and more settled temps come in. For rosebushes already growing with foliage and buds in pots, I like to wait until just after Mother's Day in my area (Colorado Zone 5) and plant them then. Here is a link to an article I wrote that may be of interest to you: https://www.gardeningknowhow.com/ornamental/flowers/roses/planting-rose-bushes.htm
Stan The Roseman