How to Amend Soil for Roses

Select a site in your landscape that receives at least six hours of full sunlight, preferably in the morning, with some shade from the sun in the afternoon. The morning sun will dry the foliage if wet from dew or morning watering so as to decrease diseases. The site should be well-drained. Avoid sites with slopes or hills.

Remove grass, weeds, rocks and debris from the selected site with a tiller or shovel. If you use a weed or grass killer, follow the directions on the label and wait the allotted amount of time before planting the roses.

Conduct a soil test by obtaining a soil-testing kit from your local extension office. You can also take a soil sample to the extension office and the staff can perform the test for you. The ideal soil pH for growing roses is 5.5 to 7.0, according to Ohio State University Extension. Refer to the test results as to which additional products you may need to amend the soil in addition to organic matter and superphosphate.

Spread a 4-inch layer of organic matter, such as compost, peat moss or manure, over the native soil with a gardening fork or shovel. This will improve drainage issues and provide necessary nutrients.

Spread 3 lbs. of superphosphate per 100 square feet of the planting area over the organic matter to promote root growth. Mix the amendments together with a shovel or gardening fork to a depth of 12 inches.