Nantucket is known for it’s beautiful flower gardens and one of the most popular must-have plants for your garden is the blue hydrangea. Who doesn’t love big blue flowers? These versatile shrubs produce giant ball-shape flowers that look stunning in landscapes surrounding your home and make gorgeous bouquets.
Some hydrangeas are like chameleons and can change their color depending on the soil they are planted in. These flowers get their color from the pH in the soil. By adjusting the pH, you can change blue flowers into pink or vice versa. Cool right? Here’s what you need to know:
1. Choose the Right Kind of Hydrangea
Only the flowers of bigleaf Hydrangea Macrophylla can change color. These shrubs are also known as Mopheads and Lacecaps.
2. Choose Blue Varieties
Look for hydrangeas that are bred to be blue such as Endless Summer The Original, Endless Summer Twist-n-Shout, Blue Danube, Penny Mac, or Nikko Blue.
3. Measure the Soil pH
Use a soil test kit to determine the current pH levels of your soil. All soil has a pH value which measures the acidity or alkalinity. The pH scale is from 0 to 14; 7 is neutral. Soil pH values of less than 7 indicate degrees of acidity. Soil pH values greater than 7 indicate degrees of alkalinity.
4. Pick the Shade of Color You Want
For true blue flowers, the hydrangeas need to be grown in acidic soil pH 5.5 and lower. For pink flowers, the plants need neutral to alkaline soils pH 6.5 and higher. For purple blooms or a mix of blue and pink flowers on the same plant, the pH of the soil must be between 5.5 and 6.5 pH. Depending on the size of your plant and your soil conditions, you may need to apply it a few times so be patient.
5. Adjust the Soil pH
To get blue blooms, you will need to amp up the soil’s acidity; sprinkle ½ cup garden sulfur over the soil beneath the hydrangea, and water it in. To get pink blooms, you will need to amp up the soil’s alkaline by adding garden lime and adding water. You can also purchase a product like Bailey’s Color Me Blue (soil sulfur) or Bailey’s Color Me Pink (garden lime) to change the pH of the soil. These all-natural products make the soil more acidic for blue blooms or alkaline for pink blooms.
6. Continue to Acidify the pH for Blue Blooms
Soil pH needs to be regulated to produce consistently blue blooms. Work pH soil additives into the top layer of the soil around the root zone to help keep the flowers the color you want.
7. Propagate Hydrangeas to Spread Happiness
To ground layer, select a branch close to the ground. Remove the leaves (approximately 5 to 6 inches) at the spot where the branch touches the ground and scrape a little of the bark off the under-side of the branch in this area. Make sure at least one leaf node will be under the ground. The leaf node is where a leaf comes out of the branch and most roots will form.
Do not cut the branch off the mother plant. Dig a little trench about 2 inches deep and lower the branch into it and cover generously with potting soil or rich loam. Put a brick or stone on the buried area so that it will stay under the soil. This will help hold the moisture around the branch. Water occasionally. When roots form, the branch can be removed from the mother plant and transplanted to another area. You may need to give the new hydrangea a little TLC in the beginning but once the roots take you will only need to water it. Hydrangeas don’t require a lot of care which is why so many people enjoy growing them.