This Is the Best Time to Plant Hydrangeas for Lush, Long-Lasting Flowers

A mature hydrangea never fails to impress with its enormous, show-stopping blooms. But achieving that type of success with a mature plant starts at the very beginning, right when you plant it. Ahead, our gardening experts explain the best (and worst) times to plant hydrangeas, along with helpful tips for ensuring success as you care for your shrubs. 

The Best Time to Plant Hydrangeas

Although it depends somewhat on your location, there are generally two ideal times to plant hydrangeas each year. "In my opinion, the best time to plant hydrangeas is either early spring (April to May) or early fall (September to October), depending on your region," says horticulturist Kate Walz. The cooler temperatures and more consistent moisture reduce transplant stress in those two seasons. "Spring planting allows the shrub time to grow and settle in before the summer heat. Early fall planting allows the shrub's roots to establish themselves before winter dormancy," she says. 

The time of day is also important when planting hydrangeas. Walz recommends planting your hydrangeas in the early morning or late afternoon to avoid stressing the plant with the intense heat of the midday sun on their first day in the ground. 

When Not to Plant Hydrangeas

Winter and summer are the worst times to plant hydrangeas. Winter isn't a good choice because it's too cold and the ground is frozen solid in many zones. Summer is also less than ideal because the heat and humidity put stress on newly planted hydrangeas.

Planting Tips 

Keep these planting tips in mind to ensure your hydrangeas start on the right foot and establish quickly.

Focus on the Soil

The road to success partially lies in your soil. "Hydrangeas love well-draining, moisture-retaining soil," says Walz. "If you have sandy or heavy clay soil, be sure to add some compost or leaf mold to help change the soil structure. The organic matter will break down, causing the soil to become better at retaining moisture, draining more freely, retaining nutrients, and promoting better aeration."

Plant for Success

Planting hydrangeas isn't difficult, but keeping these steps in mind will ensure their success. "Dig a hole twice as wide and deep as the pot," says gardening author Anne Reeves. "Add compost and soil to the bottom of the hole. Plant the hydrangea so that the base of the shrub is level with the ground. Fill the hole with soil, packing gently. Water thoroughly and spread mulch at the base of the plant."

Don't Bury the Crown

Planting hydrangeas too deep can cause future issues. "When planting a hydrangea in a nursery pot, be sure to plant it just as deep as the pot," says Walz. "In other words, do not bury the crown of the plant. The top of the crown and root ball should be level with the surrounding soil." 

Observe the Light

Before planting, observe how the sun and shade move throughout your garden during the day. Ensure you choose a hydrangea that aligns with your garden's sun exposure, as some varieties prefer more sun than others. For example, panicle and macrophylla hydrangeas tolerate more sun, while oakleaf and smooth hydrangeas need more shade, says Walz. That said, most hydrangeas perform best in morning sun and afternoon shade. "Avoid areas with hot afternoon sun or full shade," Walz adds. 

Consider Soil pH

Conduct a soil test to determine the pH of your soil, which can change the color of your hydrangeas, depending on the variety. A pH of 5.5 and lower may result in blue flowers, while a pH above 6.0 may create pink blooms. 

Care Tips 

Once your hydrangeas are in the ground, keep these pruning, fertilizing, watering, and mulching tips in mind to help them reach maturity.

Prune Carefully

Hydrangeas have different pruning needs depending on the type you grow. For example, bigleaf hydrangeas bloom on old wood (stems that set their buds the year before), so pruning in spring will cut off the season's blooms. On the other hand, panicle hydrangeas bloom on new wood (stems cut within the same growing season). "For these, it is safe to prune in late winter or early spring for the most flowers," says Walz.  

Fertilize Annually

Hydrangeas are heavy feeders that benefit from a nutrient boost in early spring. "Clean out dead wood in early spring and feed with an organic fertilizer," says Froehlich. She adds that bone meal and compost are effective natural fertilizers. 

Water Regularly

Hydrangeas need consistent moisture and struggle in dry soils. "During the first season, as the shrub continues to get established, be sure to water deeply and regularly," says Waltz. "Once the shrub is established, water an inch a week or more to maintain proper hydration." 

Maintain the Mulch

Mulch helps soil retain moisture, meaning you'll need to water less. But as the seasons progress, the mulch will break down and need to be replaced. "Apply a layer of mulch around the base of the plant (never covering up the crown) to conserve moisture and regulate soil temperature," says Walz.