Hydrangeas (Hydrangea spp.) are beautiful flowering plants grown for their large blossoms. Hydrangea flowers can be either pink or blue, and the color of the blooms depends on the pH of your soil. In acidic soils, hydrangeas have bluish blooms; in alkaline soils, hydrangeas have pink blooms.
Hydrangeas are acid-loving plants, meaning that they prefer to grow in soil that is acidic. Most hydrangeas are native to North America and Asia, where the soil tends to be more acidic, but there are some varieties of hydrangea that thrive in more alkaline soils.
What is Soil pH?
Soil pH is a measure of the acidity or alkalinity of the soil. The term “pH” is an abbreviation for “potential hydrogen,” referring to the concentration of hydrogen ions in the soil. Soil pH is measured on a scale from 1-14, with 7 being neutral and values below 7 indicating increasing acidity and above 7 indicating increasing alkalinity.
Hydrangeas prefer acidic soils with a pH around 5.5-6.5, so you will want to test your soil and see if it falls into this range before planting your hydrangea bushes. If your garden has naturally high levels of lime (calcium carbonate) or other alkaline materials such as crushed rock dust, then it’s likely that your plants will need some adjustments made by adding peat moss or other organic matter to lower their pH level slightly (to between 6 – 6 1/2).
Hydrangeas and pH
Hydrangea is a flowering shrub that produces colorful flowers in shades of white, blue, and pink. Hydrangeas are acid-loving plants, meaning they grow best in soil with a pH between 6.5 and 7.0. If the soil pH is too high or low, the plant may not bloom its full potential or could even die from poor growing conditions. You can change your soil’s pH by adding fertilizer to your garden before planting hydrangeas as well as during their growing season if needed.
Changing Hydrangea Soil pH Levels
As with all plants, hydrangeas have a preferred soil pH range. Hydrangeas prefer to grow in a soil pH of 6.0 to 7.0, which is slightly acidic. Adding sulfur or aluminum sulfate will lower the soil’s pH while lime will increase it.
If you are planting your hydrangea bush in an established garden bed that has already been planted, then the existing soil will likely be fine for growing these plants without any changes being necessary (unless your area has very alkaline soils). If you are starting from scratch, it can be helpful to know what type of soil you have so that you can amend it accordingly when planting and maintaining your new hydrangea bushes
Adding sulfur or aluminum sulfate to soil will lower pH and you can add lime to increase pH.
Hydrangeas are acid loving plants, and grow best in acidic soil. If you have alkaline soil (a pH above 6), adding lime will lower the pH to a more acidic range. Hydrangeas grown in alkaline soils may have little or no flowers because they require additional nutrients that aren’t available in the soil. Adding sulfur or aluminum sulfate will lower the pH of your soil, but this should only be done if it is too high for hydrangeas to thrive (pH of 7 or higher).
To increase your lawn’s acidity:
- Spread 1 pound of sulfur per 1,000 square feet. Sulfur can be applied as a dry dusting on the lawn surface or mixed into the top 2 inches of soil before seeding a new lawn; however, do not apply sulfur when temperatures exceed 90 degrees Fahrenheit (32 degrees Celsius). Sulfur breaks down quickly during cold weather so it won’t build up over time like other fertilizers do—which means you don’t need to worry about applying it every year.* Water well after application.* Remember not to use any other fertilizer containing nitrogen while applying sulfur unless directed by a professional garden center specialist.
Hydrangea bushes are not toxic to pets or humans. In fact, it is one of the safest plants that you can grow in your garden. Hydrangea is also a very popular choice among florists due to its showy blooms and the ease with which they can be dried without losing their color.
The hydrangea bush is a well-known deciduous shrub that blooms in summertime, making them a great addition to any flower bed or border. They’re also quite easy to care for as they require little more than water and sunlight. If you want an easy way to get started growing these beautiful plants, start by checking out our selection of hydrangeas.