Roses (Rosa spp.) grow in much of the United States, but not every location has the right type of soil for them. Roses like their soil to be at a pH level of 6.0 to 6.5, which is just slightly acidic. You can amend your soil to change its pH and provide a better home for your roses.
Roses, like many plants, need slightly acidic soil.
Roses and Soil pH
The right soil environment will help your roses get the right nutrition. That's because roses planted in soil with a pH of 6.0 to 6.5 will get just the right amount of iron, nitrogen, manganese and other nutrients roses need to grow and flourish for years to come. Depending on the variety, roses grow in U.S. Department of Agriculture hardiness zones 3 to 11.
The best way to know if your roses are getting the right pH is to test your soil. Using a trowel, dig up a handful of soil at a dozen or more spots around your garden. Mix the soil together and let it dry. To test the soil, get a home pH test kit from a garden center or send it to your local cooperative extension service for testing.
As a general rule, soils in the eastern half of the U.S. tend to be in the slightly acidic range, while soils in the western U.S. tend to be slightly alkaline. Soils can vary within geographic areas, so it's important to check the pH level in your garden.
When to Change the pH
The best way to know if the soil in your rose garden is not the right pH is to look at the health of your roses. If your roses are regularly watered and are fed with an organic fertilizer designed for roses and they look happy, then your pH is probably correct.
However, if your roses still look unhealthy, then you may need to amend your soil. Once you find out your soil's pH, you can add ingredients to your garden to alter the pH. If your soil is too acidic, add lime to make it more alkaline. If it's too alkaline, you can add a soil amendment designed to make your soil more acidic. Follow the directions and only add the amount specified, as all of these ingredients can damage plants if you add too much.
Also, make sure your rose garden soil has plenty of organic matter. Adding compost or manure for flowers will increase the soil's ability to drain water and hold nutrients for the plants.
Prepare the Rose Bed
When planting your roses, make sure your soil has good drainage. Heavy, clay soils that do not allow water to drain will be just as bad for your roses as an improper pH level. If you have clay soil, dig out the soil twice as deep as recommended when you're planting roses and then amend that soil with compost.
This preparation should give your soil an adequate pH, nutrients and drainage. Fertilize according to the type of rose you plant. Make sure you mulch your roses to hold moisture in the soil and to limit weed growth.
Deadhead your roses once the blooms are spent. Prune your roses according to the variety you have to keep your roses healthy for many growing seasons to come.
Karen Gardner spent many years as a home and garden writer and editor who is now a freelance writer. As the owner of an updated older home, she jumps at the chance to write about the fun and not-so-fun parts of home repair and home upkeep. She also enjoys spending time in her garden, each year resolving not to let the weeds overtake them. She keeps reminding herself that gardening is a process, not an outcome.