How to Grow Double Knockout Roses

Double Knockout roses are an ideal landscape rose. Upright shrubs that form a tidy mound 3 to 4 feet high and wide, they bloom from June to the first hard frost and are hardy in zones 5 to 9. Double Knockout roses have twice as many petals as regular Knockout roses. Like all Knockout roses, Double Knockout roses are not fussy about soil, have self-cleaning flowers (no deadheading!), and need very little maintenance. An added bonus--Double Knockout roses are resistant to rust, black spot and powdery mildew. Double Knockout roses look best planted in groups of three or more and can be planted to form low hedges.

Difficulty: Easy

Instructions

Things You'll Need:

• Double Knockout rose
• Shovel
• Rotted manure or compost
• Organic fertilizer
• Pruning shears

Growing Double Knockout Roses

1. Select a well-drained site in full to partial sun. If you choose partial sun make sure your roses receive at least six hours of direct sun a day. Afternoon shade is better than morning shade.

2. If you have clay or sandy soil work well-rotted manure or compost into the planting site. Dig a hole twice as wide and twice as deep as the root ball. Mix the manure or compost with the soil you have removed. Back fill the soil until you have a hole the same size or slightly larger than the container the rose is in.

3. Plant the rose at the same depth as it is in the container. Space plants three feet apart.

4. Fertilize with an organic rose fertilizer once a month.

5. Keep Knockout Roses moist at all times. Water around the roots rather than overhead.

6. In spring trim any broken or dead branches. You can shape the Knockout rose at this time.

7. In zones with cold, wet winters, give your Knockout rose winter protection by planting on the leeward side of buildings or walls. Or you can wrap snow fencing loosely around the rose and cover with straw.

Tips & Warnings

• Use organic fertilizer rather than synthetic fertilizers. Synthetic fertilizers can promote weak growth, and your rose will have more foliage and less flowers. Even though Double Knockout roses are disease-resistant, they still need adequate air circulation, created by properly spacing plants.
• Overhead watering can encourage powdery mildew.

Resources

• Double Knockout Roses