How to Grow Moonrock Hydrangea - Plant Care & Tips

By NorwichGardener Team   /   2025

Moonrock hydrangea is a beautiful, easy-to-grow shrub that is perfect for any landscape. With its large, round flowers and lush foliage, it adds a touch of elegance to any garden.

How to Grow Moonrock Hydrangea - Plant Care & Tips

Popular name

  • Snowball hydrangea
  • Oakleaf hydrangea
  • Peegee hydrangea
  • Panicle hydrangea
  • Smooth hydrangea

Things to Know

  • Moonrock hydrangeas are beautiful, flowering plants that are native to East Asia.
  • They are also known as hirsutum hydrangeas or hair hydrangeas.
  • Moonrock hydrangeas grow best in partial to full shade and moist, well-drained soils.
  • These plants produce large, white flowers that are borne in clusters.
  • The flower clusters can be up to 18 inches wide and are very showy.
  • Moonrock hydrangeas are deciduous plants and will lose their leaves in winter.
  • They are relatively easy to care for and are low maintenance.
  • Moonrock hydrangeas are generally pest and disease free.
  • These plants can reach a height of 6-8 feet and a width of 4-6 feet.
  • Moonrock hydrangeas make excellent additions to any garden or landscape.

How to Grow

  1. For moonrock hydrangea, first step is to plant the shrub in early spring before new growth begins.
  2. Choose a location with full sun to partial shade and well-drained soil.
  3. Dig a hole that is twice the width and depth of the shrub’s root ball.
  4. Remove the shrub from its container and loosen any tightly packed roots.
  5. Place the shrub in the hole and backfill with soil.
  6. Tamp down the soil gently and water thoroughly.
  7. Mulch around the base of the shrub to help retain moisture.
  8. Fertilize in early spring with a balanced fertilizer.
  9. Prune in late winter or early spring to shape as desired.
  10. Enjoy the beautiful blooms of moonrock hydrangea all summer long!

Soil Requirement

About soil condition, the Moonrock Hydrangea grows best in rich, moist, well-drained soil, but it is also tolerant of average conditions. It prefers full sun to partial shade but can also tolerate full shade.

About light

So, like the other hydrangeas, the moonrock hydrangea requires sun to thrive. Without sun, the plant will become leggy and produce fewer flowers. It's best to plant this hydrangea in an area that gets at least six hours of sun each day.

The Temperature

The temperature condition that is best for the moonrock hydrangea is one that is cool and humid. This type of hydrangea does not do well in hot and dry conditions. It is important to make sure that the moonrock hydrangea is in a spot where it will not be in direct sunlight for long periods of time.

Ideal Humidity

Ideal humidity condition for this plant is 50%. The plant should be watered when the soil feels dry to the touch. If the leaves begin to turn brown, it is an indication that the plant is not receiving enough water.

The Fertilizer

About fertilizer, this kind of plant need high phosphorus fertilizer in early spring. And we need to apply it to the whole root area around the plant. The best way to do this is to dig a hole that is twice the size of the plant's root ball.

About light

Pruning your moonrock hydrangea is important to keep the plant looking its best. You should prune the plant in early spring, before new growth begins. Cut back all of the dead and damaged branches, and then trim back any remaining branches to the desired length.

The Propagation

Propagation : Moonrock hydrangeas can be propagated by rooting stem cuttings. Cuttings should be taken from new growth and should be 4-6 inches long. Cuttings should be taken from the tips of the stems. The bottom leaves should be removed and the stem should be dipped in rooting hormone. The cuttings should be planted in a well-drained potting mix and kept moist.

Growth Speed

Usually, the plant growth rate is in the moderate range. However, they can grow quite rapidly in the right conditions. Full sun and moist, well-drained soil will produce the best growth results. This plant is very tolerant of different soils, including clay. It is important to keep the soil moist, especially during hot, dry weather.

The Problems

Common problems for this kind of plant are powdery mildew, rust, and leaf spot. These problems are all caused by fungi and are easy to spot. Powdery mildew looks like a white powder on the leaves and stems of the plant. Rust is a red or brown powder that appears on the leaves and stems. Leaf spot is a brown or black spot that appears on the leaves.

Growing Tips

  • Make sure to plant moonrock hydrangea in rich, well-drained soil.
  • Add organic matter to the soil to help retain moisture.
  • Moonrock hydrangea prefers full sun to partial shade.
  • Water regularly during the growing season.
  • Fertilize moonrock hydrangea monthly with a balanced fertilizer.
  • Prune moonrock hydrangea immediately after flowering to shape the plant and encourage new growth.
  • Deadhead spent flowers to keep the plant looking tidy.
  • Watch for pests and diseases and treat accordingly.
  • Propagate moonrock hydrangea by stem cuttings.
  • Enjoy the beautiful flowers of moonrock hydrangea in your garden!

Substitution

  • Moonrock Hydrangea - Hydrangea macrosiphon
  • Moonrock Hydrangea - Hydrangea involucrata
  • Moonrock Hydrangea - Hydrangea serrata
  • Moonrock Hydrangea - Hydrangea macrophylla
  • Moonrock Hydrangea - Hydrangea serratifolia
  • Moonrock Hydrangea - Hydrangea paniculata
  • Moonrock Hydrangea - Hydrangea aspera
  • Moonrock Hydrangea - Hydrangea arborescens
  • Moonrock Hydrangea - Hydrangea glabra
  • Moonrock Hydrangea - Hydrangea seemannii

Source:
Growing Hydrangeas - Center for Agriculture, Food, and the …
Hydrangea - University of Connecticut
Take a Look at Hydrangeas - Penn State Extension

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Reviewed & Published by Richelle
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Shrubs Category