Annuals are replanted every year, therefore, it is suggested that mulch that rapidly decays when worked into the soil be used. Tree bark and stone interfere with the planting of annuals.
Perennials should be mulched two times a year; winter and summer. The summer mulch helps to prevent water loss and control weeds. The winter mulch prevents the freezing and thawing cycles, which cause the plants to heave, which in turn kills plants.
Apply the summer mulch before the plants have much new growth and water it into place. Peat moss can be used as mulch, but it repels water once it has dried out.
Apply the winter mulch after the ground has frozen. The winter mulch should be a loose material, such as straw, in order to allow air filtration. Remove the winter mulch in the spring as soon as new growth begins. If using leaves, use only stiff leaves such as Oak or Beech. Soft leaves, such as Maple, pack together making it difficult for air and water filtration.
Bulbs benefit from winter mulching. Use approximately 4 inches of a non-packing mulch, applied when the ground is frozen. The mulch should be removed in early spring.
Most rose bushes are not hardy in northern areas, therefore, they
must be protected from both cold winter temperatures and harsh winter winds. Insulators such as burlap wraps, cones, mulch, soil, etc. provide the necessary protection.
To protect roses using soil, after the first hard frost mound soil around the base of the canes. To reduce wind whipping, either tie the canes together or cut the canes to a manageable length and mound soil 8 to 10 inches around the canes. To avoid injuring the roots, use soil from another part of the garden. Clay and other heavy soils should not be used as it holds too much moisture. After the ground has frozen, pile leaves, straw or other such materials over the mounded canes and hold them down with soil. By doing this, the soil temperature will remain constant. It is important to apply the leaves, straw, etc. after the ground has frozen to prevent mouse infestation.
Cones should be applied after the roses are dormant, which is usually after the second hard frost. If open topped cones are used, tie the canes together and fill them with leaves or straw. Cut the canes even with the top of the cone and cover with polyethylene or a similar material. For closed top cones, tie the canes together, apply leaves or straw, and then cover the rose with the cone.
To protect climbing roses, lay the canes on the ground and cover them with several inches of soil.
Tree roses should be protected by covering the plant with soil. Carefully dig on one side of the plant until it can be pulled over to the ground. Care must be taken to prevent breaking the root connection.
In the spring, after all of the danger of frost has passed and before new growth has begun, carefully remove the protective cones, soil, etc.