You will want to remove a bucket worth of soil from where the problem plant was growing but adding some compost to the area and working the soil to remove all weeds and fallen leaves will be your best insurance for new plants. Try not to plant a rose in this same location. A perennial such as a daylily or a flowering shrub such as hydrangea or hibiscus will be less likely to get a disease if planted in the same spot as the sickly rose. Keep growing, Marianne Binetti