Panicle Hydrangeas - A Growing Guide for Hydrangea Paniculata

When to plant:

Plant panicle hydrangeas during milder months in spring or fall to avoid transplant shock from extreme cold or summer heat.

Where to plant:

Place in a spot that receives at least 4 to 6 hours of direct sun during most of the growing season. More light is preferable to insure robust growth and more prolific blooms. In hotter climates, provide afternoon shade to prevent leaf scald.

How to plant:

Loosen soil in the planting area and amend with compost or other rich organic matter. Dig a hole twice as wide and slightly deeper than the root ball. Remove plant from the nursery container and loosen roots if potbound. Place in the hole so the top of the root ball is level with the surrounding soil. Fill in the hole with soil, tamp down gently to remove air pockets, and water thoroughly. Provide regular water until plants are established.

Planting hydrangeas in pots:

• Use a bagged potting mix rather than garden soil.
• Mix in a slow-release fertilizer.
• Leave 1 to 2 inches between the top of the soil and the rim of the pot for watering.
• Make sure the pot has drainage holes and has room for the plant to grow.

Learn more about growing hydrangeas in pots.

How to prune panicle hydrangeas:

Panicle hydrangeas bloom on the current season’s growth. Plants look best when allowed to grow into their natural shape and size. If desired, plants can be pruned back by up to one-third of their size in early spring as new growth is emerging. Remove dead, diseased, or errant branches and shape as needed. Cut branches to just above a leaf bud. For panicle hydrangeas trained into a tree form, avoid cutting into the trunk. (Read more on how to prune tree form hydrangeas.)

Temperature:

This shrub performs best in cool to moderate temperatures. Flowers may turn brown in hotter climates when nighttime temperatures are consistently at 70 degrees F or above.

Soil:

Panicle hydrangea is tolerant of a wide range of soils including clay, though good drainage is essential to prevent root rot. Soil pH can be slightly acidic to alkaline. Unlike bigleaf hydrangea (H. macrophylla), the flower color is not sensitive to soil pH levels. Amend soil with compost or other rich organic matter at the time of planting. Plants are shallow rooted and will benefit from several inches of bark mulch applied around the base each spring to keep roots cool, suppress weeds, and retain moisture.

Amendments and fertilizer:

Panicle hydrangea needs little or no supplemental fertilizer. To promote vigorous growth, apply a slow release granular fertilizer in spring that’s especially formulated for trees and shrubs according to instructions.

Water:

Panicle hydrangea prefers moist conditions. Don’t allow the soil to dry out, especially during bloom time, as flowers may turn brown. Provide supplemental water during prolonged heat or dry spells. Avoid overwatering, as panicle hydrangeas can develop root rot with too much water.

Pests and diseases:

When grown in the right conditions, panicle hydrangeas are free of most pests and diseases. Pests can include aphids, mites, scale, slugs or snails. Diseases include bacterial wilt, bud blight, leaf spot, powdery mildew, and rust.

For borders and landscapes: Grow in a mixed border, woodland garden, foundation planting, as hedging or screening, in mass plantings, or as a stand-alone accent in a lawn.

For slopes and hillsides: Mass along a slope, hillside, or steep bank to help stem erosion.

For containers: Smaller specimens including bush or tree types can be grown in containers on a deck or patio, or as a focal point in the landscape.

There are many ways to use panicle hydrangeas in your landscape. Here’s how:

• Use a taller variety as a background plant in a mixed border.
• Plant a larger showy specimen in an island bed to break up a large expanse of lawn.
• Plant a smaller to medium sized variety as hedging to divide garden rooms.
• Grow a small to medium-sized variety in a foundation planting with other shrubs that bloom at different times for season-long color.
• Plant a larger specimen at the end of a pathway as a focal point to draw the eye through the landscape.
• Line a pathway with a small or medium-sized variety for a long-lasting showy display.
• Place a dwarf or tree form in a decorative container and display on a deck, patio, or near an entryway for a dramatic focal point.
• Plant a medium to large variety in a row as screening along a fence or property line.