When Should Hydrangeas Be Fertilized In Ontario?

Hydrangeas are a type of plant that can be identified by their flower cluster form. They have three common shapes: lacecap, lacecap with flattened heads and small fertile central florets, and showy steril. Fertilizing hydrangeas is crucial for healthy growth and abundant blooms. Use a balanced slow-release fertilizer in spring or early summer and avoid over-fertilization to avoid too much nitrogen.

Fertilizing hydrangeas twice a year, once in early spring (May) and again in early summer (July). Most hydrangeas can be grown using nursery-standard NPK ratio 10-10-10 or 15-30-15 fertilizer. When to fertilize hydrangeas depends on whether they are planted in the ground or in pots. For optimal growth, bloom production, and quality, fertilize three times: in early spring when plants are just leafing out, in early May to boost flower production for summer, and in late June/early July to help finish the summer strong.

For best results, plant hydrangeas in the early spring or fall, following the instructions on the plant tag. Don’t apply fertilizer to any type of hydrangea after mid-August to avoid encouraging late season growth. Spring is the best time to start fertilizing hydrangeas, and hydrangeas should be lightly dressed with fast-release fertilizer in March, May, and July. Annabelle hydrangeas should be pruned in late fall or early spring before new growth appears.

For the best care, water hydrangeas in the morning or later in the evening when temperatures are at their coolest. Hydrangeas don’t require a lot of food, so they should be fertilized at least once a season in late winter or early spring.