Bloom struck hydrangea is a deciduous shrub that is native to Japan. It is a popular plant in gardens and landscapes. The bloom struck hydrangea has large, showy flowers that bloom in summer. The flowers are white, pink, or purple, and they are borne on long, arching stems. The bloom struck hydrangea is a fast-growing plant and can reach heights of 6 feet or more.
Related plant:
Blooming Bushes
About soil condition, there are four important points for bloom struck hydrangea. First, the soil should be well drained because the roots do not like to stay in wet, mucky soil. Second, the soil should be high in organic matter because it helps the plant retain moisture and provides essential nutrients. Third, the pH of the soil should be around 6.0 to 6.5 because hydrangeas prefer slightly acidic conditions. Fourth, the soil should be kept evenly moist, but not soggy, during the growing season.
Like the other hydrangeas, the Bloom Struck Hydrangea requires a minimum of 4 hours of direct sunlight per day in order to produce the best blooms. Too little sun will result in fewer blooms, and the blooms that are produced will be smaller. If you live in an area with hot summers, some afternoon shade will be appreciated.
The temperature condition that is ideal for bloom striking hydrangeas is between 60 to 70 degrees Fahrenheit. This is the temperature range in which the flowers will open and close the most, allowing for the best absorption of color. The flowers should be placed in a location where they will receive indirect sunlight for at least six hours per day.
Ideal humidity condition for this plant is 50%. If the humidity drops below 30%, the flowers will wilt and the leaves will curl. If the humidity stays above 60% for more than a week, the flowers will start to rot.
Regarding fertilizer, this plant does best with a slow-release fertilizer or one that is low in nitrogen. An ideal fertilizer for a bloom-struck hydrangea would have a ratio such as 8-8-8 or 10-10-10. In terms of roots, the plant prefers moist, well-drained soil with a pH between 5.5 and 6.5.
Pruning is an important part of keeping your bloom struck hydrangea healthy and blooming beautifully. You can prune off any dead or faded blooms, as well as any crossed or crowded branches. In late winter or early spring, you can give the plant a more drastic pruning if needed. This will encourage new growth and more bountiful blooms.
Propagation of hydrangeas is typically done through rooting stem cuttings taken from the desired plant. However, bloom struck hydrangeas can also be propagated through division of the root ball. This should be done in early spring, before new growth begins. To divide the root ball, simply dig up the plant and carefully pull it apart into smaller sections, making sure each section has a good root system. Replant the sections immediately and water well.
Usually, the plant growth rate is relatively fast, with some cultivars reaching their full potential size in just a few years. However, some varieties may take up to 10 years to reach their mature height. Most varieties will continue to produce flowers for several years, with some types blooming for over 20 years.
Common problems for this kind of plant are powdery mildew, rust, and leaf spot. These can all be controlled with the proper fungicide. Another problem that can occur is when the plant is not getting enough water. This will cause the leaves to turn yellow and eventually drop off.
Source:
Pruning hydrangeas for best bloom | UMN Extension
Hydrangea - North Carolina Extension Gardener Plant Toolbox
Hydrangea macrophylla Why Wont It Bloom? - Kansas State