Properties of Peat Moss

• Peat moss is an acidic bog plant with large cell structure. The Canadian Sphagnum Peat Moss Association points out that the large cell structure that peat moss exhibits is what allows it to absorb and hold moisture, to absorb nutrients for later distribution, and absorb air. It is not the growing plant that is harvested for peat, but the decomposing layer underneath the growing mat.
  
  

Mulching Roses with Peat Moss

• The website Old Garden Roses and Beyond cautions against using peat moss as a mulch for rose beds. Peat moss has a tendency to wick moisture away from the root zone, according to the Department of Horticulture at Cornell University. However, this means that peat moss can be used in areas where the soil tends to hold too much water. If used as part of a mulch mix, work it towards the bottom of the mix so that it does not blow away or dry out too quickly. Peat moss does not readily absorb moisture again when it is allowed to dry out completely.
  
  

Peat Moss in Rose Soil Mixes

• According to the website Old Garden Roses and Beyond, "peat moss can hold water and nutrients ten to fifteen times its own weight when fully saturated and can still hold 40 percent air." If you are growing high-maintenance roses and are constantly adding nutrients, the nutrient-holding properties of peat moss prevents nutrient leech or runoff. Peat moss will generally decompose in about five years. This is one of the reasons why it's not recommended to plant a new rose in an old rose hole.
  
  

Peat Moss and Rose Cuttings

• Cornell University's Department of Horticulture advises using peat moss as a starter for cuttings because it is a sterile substrate. This makes it ideal for rose cuttings that are particularly sensitive to disease. Rose cuttings are also sensitive to burning in nutrient-rich medium while establishing. Peat moss does not have nutrients of its own, and can evenly disperse nutrients once the cutting is ready for them.
  
  

Alternatives to Peat Moss in the Rose Garden

• According to the Institute of Food and Agricultural Sciences at the University of Florida, coir dust, or the small particles from the husk of coconut shells, is a more environmentally sustainable alternative to peat moss. It is comparable or superior to peat moss in water retention; it does not decompose as quickly and absorbs water readily even if dried out. If the soil in your rose garden is already acidic enough, coir is preferable to peat moss because it does not acidify the soil. The University of Arkansas is researching the use of rice hulls, an agricultural by-product, as an alternative for peat moss because it also has similar properties.