Hydrangeas are hardy perennials, most commonly recognized for their lush and abundant flowerheads. The fluffy flowerheads of hydrangeas consist of numerous star-shaped flowers that are packed closely together, giving them their unique and exuberant appearance. The Hydrangea genus contains 70-75 different species, the most popular being Hydrangea Macrophylla. Although most species of hydrangeas produce a white flower and bloom mid-late summer, certain species of hydrangeas bloom at different times and vary in colour.
Quick Facts About Hydrangeas:
- Indigenous to Southern and Eastern Asia
- Plant type: Deciduous or Evergreen (the cultivated species grown in Canada are all deciduous)
- Exposure: Full sun – partial shade
- Appearance: shrub, bush, tree or lianas
- Watering: Deep watering 1x week
- Size: average height of 1-3 meters
- Spacing: Give 3-6 feet proximity around each plant
- Pruning: Best pruned when the blooms have ceased (fall). Some species of hydrangea flower from ‘old wood’, ‘new wood’, or both; therefore pruning needs to be specific to that species.
Top 10 Most Popular Hydrangeas
1. Hydrangea Macrophylla ‘Annabelle’
2. Hydrangea Macrophylla ‘Incrediball’
3. Hydrangea Macrophylla Cityline Series
4. Hydrangea Macrophylla Endless Summer Original Blue & Pink (color changing)
5. Hydrangea Macrophylla Endless Summer ‘Bloom Struck’
6. Hydrangea Paniculata ‘Lime Light’
7. Hydrangea Paniculata ‘Little Lime’ (Compact Version of ‘Lime Light’)
8. Hydrangea Paniculata ‘Quick Fire’
9. Hydrangea Paniculata ‘Pinky Winky’
10. Hydrangea Paniculata ‘Phantom’
Did you know?
Do you know what the difference between the Hydrangea species Macrophylla vs. Paniculata is? Hydrangea Macrophylla have larger leaves and rounded flower heads, they are sometimes called ‘Mopheads’ or ‘Big Leaf Hydrangeas’. Hydrangea Paniculata have smaller, thinner and rougher leaves with flower heads that resemble more of a cone shape.
Colour Changing Hydrangeas
Hydrangeas are fascinating and unlike most plants because the colour of their flowers can change dramatically. Most species of hydrangea have white flowers, however, in some species including hydrangea macrophylla, the flower heads can be blue, red, pink, light purple or dark purple. In these species the colour of the flower head is effected by the pH of the soil. The pH of the soil is determined by the amount of aluminum ions.
- Acidic soil (low pH)- will have available aluminum ions = blue-purple hydrangea flowers
- Alkaline soil (high pH)- no available aluminum ions = pink-red hydrangea flowers
Therefore, you can actually change the colour of your hydrangea plant by altering the pH of the soil.
To make soil more acidic, sprinkle ½ cup garden sulfur over the soil beneath the hydrangea, and water it in. To make it more alkaline, do the same with ground lime. There are also products that can be bought at your local nursery to change the pH.
– Jenna Monk