| and how do I keep the blooms blue? When I bought it it was blue, last year pink |
| Hydrangea flowers can change color because of soil acidity or alkalinity. A blue hydrangea won't stay blue in an alkaline soil. Instead, it will turn pink. You can coax it back into being blue by applying 2 Tablespoons of aluminum sulphate per plant, making 4-6 applications at 2 week intervals, starting in the early spring before the plants bloom. (Sulfur will acidify the soil. The desired pH range would be between 5.5 and 6.) Best wishes with your hydrangea! |
