Hydrangea produces large clusters of pink or blue flowers in the spring. Grow the plant in moderately bright light. Adequate watering in spring promotes formation of large flower heads. During the winter rest period, provide a minimum temperature of 45 degrees and water only when the soil is quite dry. Give more water in early spring and begin fertilizing when the plants are actively growing. Temperatures below 65 degrees for 6 weeks initiate flower buds. Then plants are defoliated and given 6 weeks of complete darkness at temperatures between 33 and 40 degrees. Forcing requires 3 months of 60 degree nights and 65 to 70 degree days. A soil pH is between 4.5 and 5 and little or no phosphorous gives blue flowers. Pink flowers result from a soil pH of 6.3 to 6.5 and high levels of phosphorous. Pruning is done after flowering. If terminal buds are injured or pruned off the plant will not bloom.
Propagation is by stem tip cuttings taken from non- flowering shoots. Take cuttings any time between April and August. Each cutting needs 2 to 3 pairs of leaves. Make the cut across a node. Cuttings can be rooted in a cold frame during the summer.
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|Hydrangea macrophylla - 59K||Hydrangea macrophylla - 52K|