How to Grow Knockout Roses
Choose a location for the Knock Out rose that gets at least three hours of direct sunlight each day., Check to see if your soil drains quickly., Test the soil pH., Mix lime into the soil to raise the pH or add aluminum sulfate to lower the pH...
Step-by-Step Guide
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Step 1: Choose a location for the Knock Out rose that gets at least three hours of direct sunlight each day.
While these roses are not picky, they do need sunlight to stay healthy. -
Step 2: Check to see if your soil drains quickly.
You can do this by digging an 18-inch deep hole and filling it with water.
Check the hole after 24 hours.
If there is still water in it, find a planting site with better drainage or build a 1 to 1 1/2-foot high raised bed and plant the Knock Out rose there. , Knock Out roses grow best in soil with a pH of 6 to
6.5.Soil test kits are generally available at garden centers.
Take the soil test sample from 4 inches deep and do not touch it with your hands.
If you do touch it, your skin could change the pH of the sample.
Let the sample dry, break it up into fine pieces, place it in the pH test chamber and add distilled water along with the test chemical.
Shake it up and check the color of the water against the color chart provided with the kit. , The amount of lime or aluminum sulfate required depends on the soil type.
Sandy soil will require about 12 ounces of lime to raise the pH of 25 square feet of soil from
5.5 to 6 or about 2 ounces of aluminum sulfate to change the pH from 7 to
6.5.
More lime or aluminum sulfate must be used to change the pH of loamy or clay soil.
Sprinkle the aluminum sulfate or lime evenly over the soil and mix it in thoroughly with a tiller before planting the rose. , If the rose has already been planted but the pH needs to be changed, mix the aluminum sulfate or lime into the top 2 inches of soil with a dirt rake or hand rake.
Spread it all the way around the rose in an area that extends 3 feet away from the base of the shrub.
If the soil pH is too high, the rose may develop chlorosis which causes the leaves to turn yellow. -
Step 3: Test the soil pH.
-
Step 4: Mix lime into the soil to raise the pH or add aluminum sulfate to lower the pH.
-
Step 5: Troubleshoot if you need to change the pH when your plant is already in the ground.
Detailed Guide
While these roses are not picky, they do need sunlight to stay healthy.
You can do this by digging an 18-inch deep hole and filling it with water.
Check the hole after 24 hours.
If there is still water in it, find a planting site with better drainage or build a 1 to 1 1/2-foot high raised bed and plant the Knock Out rose there. , Knock Out roses grow best in soil with a pH of 6 to
6.5.Soil test kits are generally available at garden centers.
Take the soil test sample from 4 inches deep and do not touch it with your hands.
If you do touch it, your skin could change the pH of the sample.
Let the sample dry, break it up into fine pieces, place it in the pH test chamber and add distilled water along with the test chemical.
Shake it up and check the color of the water against the color chart provided with the kit. , The amount of lime or aluminum sulfate required depends on the soil type.
Sandy soil will require about 12 ounces of lime to raise the pH of 25 square feet of soil from
5.5 to 6 or about 2 ounces of aluminum sulfate to change the pH from 7 to
6.5.
More lime or aluminum sulfate must be used to change the pH of loamy or clay soil.
Sprinkle the aluminum sulfate or lime evenly over the soil and mix it in thoroughly with a tiller before planting the rose. , If the rose has already been planted but the pH needs to be changed, mix the aluminum sulfate or lime into the top 2 inches of soil with a dirt rake or hand rake.
Spread it all the way around the rose in an area that extends 3 feet away from the base of the shrub.
If the soil pH is too high, the rose may develop chlorosis which causes the leaves to turn yellow.
About the Author
Shirley Jenkins
With a background in realestate, Shirley Jenkins brings 5 years of hands-on experience to every article. Shirley believes in making complex topics accessible to everyone.
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