2) To maintain good vegetative growth and acid soil conditions, use ammonium sulfate as the nitrogen source at the rate of 1 lb (or 2 cups) per 100 square feet (or a little less than a ¼ cup per 10 square feet). Ammonium sulfate is the best nitrogen source to help maintain soil acidity.
How do you apply Aluminium sulphate to soil?
Work the aluminum sulfate into the soil with a shovel and then water the soil thoroughly until it is evenly moist to activate the product. The aluminum in the soil raises the acidity instantly, while the sulfur breaks down more slowly, depending on the soil temperature and the bacteria in the soil.
Does ammonia sulfate turn hydrangeas blue?
Aluminum is the element responsible for blue hues in hydrangea flowers, and when aluminum sulfate is applied around a shrub, it not only lowers the pH of the soil, but also makes aluminum more available to the plant, according to Clemson University Extension.
How much sulfur do I add to my hydrangea?
To Lower Soil pH
- In sandy soil: add 1 pound ground sulfur per 100 square feet.
- In loam (good garden soil): add 1.5 to 2 pounds per 100 square feet.
- In heavy clay: add 2 pounds per 100 square feet.
What does aluminum sulfate do to hydrangea?
One of the most effective ways to turn hydrangea blossoms blue is to acidify planting soil with aluminum sulfate. Although it is not essential to a hydrangea’s nutrition, aluminum sulfate changes the way the plant processes nutrients, resulting in flowers of a pale-to-deep blue color.
How do you apply aluminum sulfate to plants?
Mix 1/4 cup of aluminum sulfate into 1 gallon of water in a watering can to create a soil drench for an already established plant, like a hydrangea, that needs a lower pH.
How do you apply aluminum sulfate to potted plants?
Use ½ ounce (1 tablespoon) aluminum sulfate per gallon of water to plants that are at least 2 to 3 years old after thoroughly watering the soil first. Too much aluminum sulfate can burn the roots or the plants.
Can you put too much aluminum sulfate on hydrangeas?
Caution – over application of aluminum sulfate can be toxic even to hydrangea. Monitor your soil pH periodically and only apply aluminum sulfate if your pH is greater than 5.0. Non-acid loving plants growing in the vicinity of hydrangeas may not grow well if the soil pH drops too low.
How do you add soil acidifier to hydrangeas?
Or to transform established hydrangeas into blue beauties, apply 2½ cups of Organic Soil Acidifier. Spread evenly around the hydrangea out to its drip line, or the widest reaching branches. Then, water well. Repeat every 60 days until you’ve got the perfect color for you.
How do I make my hydrangea purple?
Generally speaking, acidic soil, with a pH lower than 6.0, yields blue or lavender-blue hydrangea blooms. Alkaline soil, with a pH above 7.0, promotes pinks and reds. With a pH between 6 and 7, the blooms turn purple or bluish-pink. To lower your pH, add garden sulfur or aluminum sulfate to your soil.
How do I make bone meal for hydrangeas?
Bone meal replaces depleted phosphorus and will get the plants off to a good start for summer growth. I buy mine in 4.5 lb. bags and directions say to use 1 teaspoon mixed into the dirt for bulbs. For shrubs, such as the hydrangea, apply 1 to 2 pounds (2.25 cups of bone meal equals 1 pound).
What is the best fertilizer for hydrangeas?
A good all purpose 12-4-8 or 10-10-10 composition will provide all the fertilizing hydrangeas need. Either a chemical source or organic matter can be used successfully. Applying a once a year slow-release chemical formulated for shrubs and trees is the simplest solution to hydrangea care and feeding.
How often can you apply aluminum sulfate?
The recommended application rate is 1 Tbsp per gallon of water, applied as a soil drench over the root zone. Repeat periodically throughout the growing season, every 6-8 weeks or so. Do NOT increase dosage or overapply. Too much aluminum will create toxicity and can burn the plant.
When should I fertilize my hydrangeas blue?
Mix ¼ oz aluminum sulfate with a gallon of water and soak the soil surrounding your hydrangeas in the spring, as soon as the plant begins to grow. You’ll have to maintain that acidity throughout the growing season, so reapply in 4 weeks and again in 8 weeks.
How long does it take to change hydrangea color?
It is easier to change blue flowers to pink than to change pink flowers to blue, and some cultivars are more prone to color variability than others. We recommend waiting until the plant is at least 2 years old to give it time to recover from the shock of its original planting.