Clay Soil Preparation for Roses

• Establish that your soil is, in fact, clay soil. Add enough water to a handful of soil to allow it to form a ball. Then, roll the soil between your hands to make a snake-shaped length of the clay. If you can form a two inch length and it doesn't crumble, you have clay soil.
  Once clay soil is verified, set to work amending the soil. Test the soil for PH and nutrient deficiencies before you begin to work. It's important to work clay soil as little as possible, so it makes sense to incorporate lime or gypsum and other fertilizer at the same time you're adding other fillers.
  Don't till, dig or walk on clay garden soil when it is wet. The result can mean nearly concrete-hard compaction. When the soil is dry enough to work, turn the soil with a garden fork. Break up the large clods with a sharp rap with the side of the fork. Then haul in organic material: compost, leaves, manure, and grass clippings are all good choices. Don't forget to include any soil fillers indicated by your soil testing. Gently incorporate the organic amendments to a depth of eight inches. You will need at least a four inch layer of amendments to begin with, and add more every year. Improving clay soil is an ongoing and unending job.
  Water clay soils carefully, especially if they seem to drain poorly. The organic amendments break down and combine with the ever smaller clay clods to produce a soil that permits air and water to permeate the garden bed and reach plant roots.
  An alternative to digging amendments into clay soils is to build raised beds for your roses above the clay, building your own soil with peat moss, compost and manure. Insure that you place the bed in a well-drained location and avoid low-lying areas. The beds will need to be big enough to hold soil of a depth of at least eight inches (more is better).