Importance of pH Levels During Flowering

Alkaline and Acidic Soil

• Most flower species grow best in soils that are slightly acidic or neutral on the pH scale. Any level under a pH value of seven is considered acidic; anything over seven is considered alkaline, or basic. Soil pH level is measured determining the amount of lime, or calcium, that exists in your soil. The soil must be adjusted to suit the plant or flower that will occupy that area if it is not already within that plants requirement range.

Testing Your Soil

• Determine your soil's pH level by bringing in a sample to your local garden center or purchase a home-testing kit from a nursery or hardware store to conduct your own testing. Test kits consist of a test tube, a dropper with testing solution and a test tube holder. Add a few drops of the test solution into the test tube containing your soil, wait one hour and the solution-treated soil will change color based on its pH level. Most test kits come equipped with a color chart to help with this process.

Types of Acidic Soil Flowers

• Flowering plants that prefer soil of an acidic pH level -- or a level under the neutral value of seven -- include many types available for purchase at your local nursery. For example, African violets, chrysanthemums, Impatiens and ferns all thrive in soil that is between a pH level of 5.0 and 7.0. Flowers that prefer acidic soil can be seen in most household gardens due to their commonality.

Types of Alkaline Soil Flowers

• Flowers that prefer soil with a pH level over the neutral value of seven -- an alkaline soil pH -- are much less common in comparison to their acidic soil-loving counterparts. For example, plants like cosmos, Forsythia and the day lily all prefer alkaline soil levels; however, vegetables like pumpkins, tomatoes, watermelons and mustard actually prefer alkaline soils.