Cityline ™ Rio Hydrangea blooms earlier than most hydrangeas. The Color Choice, Hydrangea macrophylla Cityline ™ Rio PPAF is another introduction to the Cityline ™ Hydrangeas by breeder Konrad Rampp of Germany. The Cityline ™ Rio Hydrangea blooms in early summer with blue to purple blossom and keeps a compact shape growing into the 3 feet tall height range and spreading 2 to 3 feet wide. The Hydrangea Cityline ™ Rio will grow in spaces with sun to partial shade. Blooms fade to a beautiful shade of green as they age.
Cityline ™ Hydrangeas bloom colors will be altered by the pH level of the soil.
Cityline™ Rio Hydrangea macrophylla 'Ragra'
For Pink blooms add dolomite lime several times a year. Shoot for a pH of 6.0 to 6.2. Above 6.4 and they may experience iron deficiency. Choose a fertilizer with a high level of phosphorus ration (such as 25/10/10).
For Blue blossoms add aluminum sulfate to soil. Authorities recommend a solution of ½ oz. (1 tsp) aluminum sulfate per gallon of water be applied to plants, which must be 2 to 3 years old, throughout the growing season. Water plants extremely well before these applications as it can burn the roots. An organic route to blue blossoms is to add coffee grounds, fruit and vegetable peels and grass clippings to the soil around the plants.
Select a fertilizer with a low in phosphorus ratio such as 25/5/30. Aim for a pH of 5.2 to 5.5. Avoid superphosphates and bone meal when attempting to control the color.
Sometimes it can be easier to control the color issues when the hydrangeas are planted in containers. Hydrangeas planted in the ground near a foundation may never produce a blue shade due to the lime leaching out from the cement.
Hydrangea Cityline ™ growing and care information: The Cityline ™ series of hydrangeas will grow in areas with sun to partial shade. They perform best in soil with high organic matter. Their water level should be monitored, as they generally require a higher moisture level than other shrubs.
After planting and plant begins to grow, pinch or clip the branch tips just enough to remove the newest growth to control branching. Repeat this through the first growing season to force the plant into producing new stems. Continue pinching or lightly shearing on into the second growing season until early August. At this time stop any pruning or pinching to the plant. This allows time for the plant to set buds for blooming next season. As the plant ages, any pruning should be done by early August or immediately after blooming.
Fertilize in spring with a slow release fertilizer.
Planting Cityline™ Rio Hydrangea Shrubs
Video on the basics for planting container grown plants:
Planting Basics for Container Grown Plants