How to Protect Roses from a Late Frost
Protect roses from a late spring frost by covering them overnight with fabric, burlap, or a cardboard box before dusk, and uncovering them in the morning. Cover tender new growth, and avoid plastic touching the leaves.
A late spring frost after roses have leafed out can damage tender new growth and buds. When frost is forecast, cover the plant before dusk — while the ground still holds the day's warmth — using a breathable material such as a frost cloth, old sheet, burlap, or an inverted cardboard box or bucket for small plants.
Let the cover reach the ground to trap soil warmth, and avoid plastic resting directly on foliage, which can worsen freeze damage where it touches. Remove the cover in the morning once temperatures rise. Frost damage often looks worse than it is; wait, then prune out any blackened growth after the danger passes. For winter cold, see protecting roses in winter.