In regions of cold winters Roses need protection. Hybrid Tea and Floribunda bush Roses will withstand a temperature of about 12 degrees F. but are likely to be damaged by alternating mild and cold spells. They can be protected by mounding soil, buckwheat hulls, or peat moss around the base of the plants, covering them to a height of at least 8 in. Where the temperature drops below zero F., they should have soil mounded up to them and, after the ground is frozen to a depth of an inch or two, a thick covering of strawy manure or leaves should be placed over this.
Tree or standard Roses will tolerate about 15 degrees F. Where temperatures drop below this, they should be laid along the ground and covered with soil and a layer of leaves, straw or other winter covering. In the most northerly regions they must be lifted and buried in a trench in the ground.
Large flowered and everblooming climbers will survive at 5 degrees F. but are best mounded as recommended for Hybrid Teas where the temperature goes lower. In colder regions it is safest to lay the shoots down on top of the ground and cover them with soil.
Climbing Hybrid Teas and Floribundas should be mounded with soil in similar fashion and, in colder regions, laid down along the ground and covered with soil and mulch.