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Do Roses Like Acidic Soil? Ideal pH & FAQs

three pink roses

Roses are one of the most beautiful ornamental plants to grow in gardens. They do well in many parts of the country and easily survive through the winter when watered properly. Roses also grow vibrantly in rich, well-drained soil in planting pots or on land. However, you must observe soil acidity to enjoy roses’ stunning pink blooms in summer. Most plants, including roses, love slightly acidic soil.

This article will explain the pH requirements of roses and elaborate more on why you should keep it at the right level.

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What Is the Perfect pH for Roses?

The pH of slightly acidic soil is between 5.5 and 6.5, which is not too high nor too low. So, the perfect pH of roses is between 5.0 and 6.5. Balancing pH at these levels will encourage vibrant growth and boost the plant’s immunity. Furthermore, roses will absorb large quantities of essential nutrients to produce bigger and more colorful flowers and cope better with attacks from insects.

Rose garden
Photo Credit By: Nikita Tikhomirov, Unsplash

What Is the Importance of Ensuring Roses Grow in Soils With the Right pH?

Being a hardy plant, roses do well in most soils since the global soil pH level is between 4 and 9. If you are lucky to be in a region with a soil pH of less than 7, you will invest less in roses’ fertilizer. In contrast, if the pH is high, then the average cost of growing them will shoot up.

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The 3 Ways Soil pH Affects Plant

1. Soil pH Affects the Availability of Nutrients

Soil pH has a direct impact on the availability of nutrients. An extremely low pH of less than 6 increases the solubility of aluminum, iron, and manganese. In high quantities, these minerals are toxic to the plant.

Additionally, low pH reduces the availability of macronutrients (nitrogen, phosphorus, and potassium). Plants lacking vital nutrients have stunted growth and take a long time to bloom. Individually, signs of lack of nitrogen, potassium, and phosphorus in roses are yellowing of leaves, limp leaves on hot days, and leaves turning blue-green, respectively.

When the pH is high (over 7.5), calcium and most micronutrients will not be available for roses. You will notice this when plants start aborting flowers, curling leaves, and browning.

2. Affects Roots Development

Roots are made up of living cells that require favorable conditions to colonize the soil. If the soil is too acidic, roots will not grow well, and this will be testified by stunted growth. Besides, low pH increases aluminum levels, which negatively affects root growth.

3. Reduces Microbial Activities

The soil is a bustling ecosystem that billions of bacteria, insects, and fungi call home. While a few microorganisms are detrimental to the plant, most of them are beneficial. An example is mycorrhizal fungi. They act as a root extension system, greatly increasing the absorptive area of a plant.

When the pH dips below 5.5, the activities of these organisms slow down. This means that the root system will be shortened, organisms that break down organic matter into nutrients will die, and the soil will be poorly aerated due to fewer burrowing activities.

a beautiful red rose
Photo Credit By: HelgaKa, Pixabay

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How Do You Test Soil pH?

Below are some of the ways to test soil pH:

  1. Contact a soil professional pH testing company who have an arsenal of equipment to provide accurate and reliable results. Additionally, experts will recommend ways of correcting the pH.
  2. Buying a soil pH testing kit and using it to test the soil. Testing kits come with a small container, strips, and a color chart. Simply take the soil and mix it with distilled water in the container. Dip the strip into the solution and observe and compare color changes with the color chart.
  3. Use a digital pH meter. It has a probe that you plug into the soil and then wait for a few seconds to bring back the results on a small digital screen. Refer to the manual to understand what they mean.
  4. Lastly, use a simple DIY method. This is not a highly accurate method but will give you the general status of the soil pH. Here is how it is done:
    • Collect two soil samples of equal portions from different areas of the garden or lawn and place them into two separate containers. For better results, collect samples randomly and avoid areas close to compost pits and hedges.
    • Add half a cup of vinegar to the soil and observe the outcome. If your soil fizzes, it’s probably alkaline and has a pH of above 8.
    • If it doesn’t, mix the soil in the other container with half a cup of baking soda and distilled water. If it fizzes, your soil probably has an acidic pH range of 5–6.
    • If no reaction is exhibited in both, your soil pH is probably okay.

How Do You Correct the Soil pH?

sprinkling limestone powder on the soil
Photo Credit By: FotoHelin, Shutterstock


There are two types of lime: dolomitic limestone (which adds magnesium to the soil) and calcitic limestone (mainly calcium carbonate). Both can effectively raise soil pH. The products come in pulverized, pelletized, hydrated, or granular forms. Ground lime is fast-acting but often clogs spreaders, while granular or pelletized lime is easy to apply but takes longer to correct pH. Hydrated lime, on the other hand, acts fast but is easy to overdose. Thus, choose a product that fits within your schedule and has less risk of harming the soil.

Wood ash

This method is for small gardens and has been in use for many years. To raise soil pH, sprinkle a pound of wood ash over a 10-square-foot area. Mix with the soil and lightly water. You can plant immediately or leave the soil for up to 2 weeks.

Lower soil pH in alkaline soil by:


The cheapest, safest, and most convenient technique to raise soil acidity is probably by adding plain elemental sulfur, which can be applied directly to the soil surface. Unfortunately, sulfur is slow-acting, and the risk of overdose is high. Do not exceed 2 pounds per 100 sq. ft at a time.

Iron Sulfate and Aluminum Sulfate

Thanks to the sulfur in these compounds, you can use iron and aluminum sulfate to raise soil pH.

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Roses do well in soil with a pH of between 6.5 and 5.5. If the soil pH is high, it will reduce the availability of macronutrients. Correct it by adding lime and wood ash. Similarly, if the pH is too low, the plant will lack vital micronutrients. You can use sulfur to lower it.

Featured Image Credit: cocoparisienne, Pixabay


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