Answer: Knock Out Roses have proven to be almost resistant to black spot, the fungal disease that is the scourge of roses across much of the United States. It is also resistant to powdery mildew and aphids. It is cold-hardy throughout the state and will grow in a wide range of soils (even highly alkaline clays) and is very heat- and drought-tolerant once established. For best growth, locate the plants where they will get good air movement over the leaves and receive eight hours or more of direct sun each day. Be sure to incorporate three to four inches of finished compost into the soil prior to planting and keep the soil surface covered with three inches of organic material year round. Enjoy!
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