How to Grow and Care for Strawberry Sundae Hydrangea

Front view of a strawberry sundae hydrangea shrub

The Spruce / Evgeniya Vlasova

Strawberry Sundae hydrangea is a cultivar that stands out from other panicle hydrangea varieties., with multicolored blooms that emerge creamy white, then change to light pink, and finally mature to strawberry red in late summer. You’ll enjoy the various stages of bloom more than once because Strawberry Sundae blooms from mid-summer to fall. With a maximum height and width of about 4 feet, this is a compact hydrangea that fits in small spaces and is a medium to fast grower. Strawberry Sundae is also one of the most winter-hardy cultivars. 

Like all hydrangeas, the plant is toxic to humans and pets.

 Common name  Strawberry Sundae hydrangea, Sundae Fraise hydrangea
 Botanical Name  Hydrangea paniculata ‘Strawberry Sundae’ (‘Rensun’)
 Family  Hydrangeaceae
 Plant Type  Shrub
 Mature Size  4 to 5 feet tall, 3 to 4 feet wide
 Sun Exposure  Full, partial
 Soil Type   Well-drained, moist
 Soil pH  Acidic, neutral
 Bloom Time  Summer, fall
 Flower Color  White, pink
 Hardiness Zones  4-8 (USDA)
 Native Area  Cultivar, no native range
 Toxicity  Toxic to humans, toxic to pets

Strawberry Sundae Hydrangea Care 

Strawberry sundae hydrangea flowers

The Spruce / Evgeniya Vlasova

Closeup of strawberry sundae hydrangeas

The Spruce / Evgeniya Vlasova

Closeup of strawberry sundae hydrangea petals

The Spruce / Evgeniya Vlasova

Strawberry sundae hydrangea flowers turned fully pink

The Spruce / Evgeniya Vlasova

Strawberry Sundae hydrangea

Salicyna / Wikimedia Commons / CC BY-SA 4.0

Strawberry Sundae hydrangea

Salicyna / Wikimedia Commons / CC BY-SA 4.0

Strawberry Sundae hydrangea

MichelR45 / Getty Images

Strawberry Sundae hydrangea

Salicyna / Wikimedia Commons / CC BY-SA 4.0

Light

For the best bloom, this shrub needs full sun. Less than six hours of sunlight results in fewer blooms and a leggy appearance. At the warmer end of the zone spectrum (more towards zone 8), direct morning sun is better than hot afternoon sun. 

Soil

Soil should be rich and well-drained, with a neutral or slightly acidic pH (between 5.8 and 6.2). The color of Strawberry Sundae is not affected by soil pH.

Water

About 1 inch of water per week, either from rainfall or irrigation is adequate, During hot weather additional watering prevents wilting. Hydrangea roots are shallow and dry out quickly but alsorecover quickly when hydrated.

Temperature and Humidity

This cultivar is winter-hardy down to zone 4. High humidity can lead to fungal diseases so pruning for good air circulation is needed to reduce moisture on foliage.. 

Fertilizer

Work two shovelfuls of compost into the soil or apply a slow-release, balanced fertilizer each spring after the plant has come out of dormancy. Withhold fertilizer after late July to discourage new growth as the shrub enters into dormancy.

Other Panicle Hydrangea Types

There are numerous other panicle hydrangea cultivars, including: 

Pruning

It is important to know that Strawberry Sundae blooms on new wood. The best time to prune is in late fall. Wait at least two weeks after the plant has dropped all its leaves. You can also prune in early spring before it starts to leaf out. 

Propagating

Strawberry Sundae is a trademarked, copyrighted cultivar and propagation by any means is prohibited. Note that the flowers of this cultivar are sterile, so it won’t produce any seeds.

Potting and Repotting

Due to its compact size, Strawberry Sundae is well-suited to containers. Choose a pot at least 16 to 24 inches wide, with large drainage holes. Since the plant remains outdoors year-round, use a frost-proof container, such as wood or plastic.

Fill the pot with potting mix and plant the hydrangea at the same level as in it's original pot. Place it in a location to receive six hours of sunlight daily. Potted plants need more frequent watering and fertilizing, about once a month during the growing season, but discontinue fertilizer after late July.

When roots reach the sides of the container, (about two years), repot in a larger container with fresh potting soil, or root-prune and repot in the same container with fresh potting mix. 

Overwintering

Strawberry Sundae hydrangea planted in garden soil does not require winter protection other than a thick layer of mulch to insulate shallow roots from the cold.

The best option for container grown shrubs is to create an insulation silo, or move them to a sheltered outdoor location. 

Common Pests & Plant Diseases 

Strawberry Sundae is vulnerable to several diseases, including bacterial wilt, bud blight, leaf spot, powdery mildew, and rust. Ample spacing and proper pruning improves air circulation and cuts down on disease spread.

If you detect aphids or mites, use neem oil to prevent an infestation. 

How to Get Strawberry Sundae Hydrangea to Bloom

Three common reasons why Strawberry Sundae does not bloom are lack of light, improper pruning, and nutrient imbalance. With less than six hours of sunlight, bloom will be poor. Move container plants to a sunnier location and cut back surrounding vegetation for shrubs grown in ground.

Too much nitrogen produces foliage but no flowers. When you fertilize in spring, use a bloom-boosting fertilizer high in phosphorus.

Pruning too late in spring also leads to reduced bloom if developing buds are removed.  

Common Problems with Strawberry Sundae Hydrangea

Strawberry Sundae hydrangea is generally free of issues. However, yellowing leaves can develop in the center part of the plant during the first season. New foliage at the top shades inner leaves causing them to fade and drop. Proper pruning to allow more light exposure in the center of the shrub remedies this problem.

Also, the large, pyramid-shaped flower panicles can cause the stems to droop. Prune to keep stems shorter, sturdier and better suited to bear the weight of the large colorful blooms.

FAQ
  • Why are my Strawberry Sundae hydrangeas white?

    This is normal. The flowers of this cultivar start out as creamy white and turn strawberry red to pink in the late summer.

  • Why is my Strawberry Sundae hydrangea not turning pink?

    The change of color from creamy to pink is triggered by cooler weather in late summer. It is likely that the nighttime temperatures in your location are still quite warm. Once nights become cooler, you should see the color change.

  • Should you cut back Strawberry Sundae hydrangea?

    Do not cut it back during the growing season, or else you will reduce the bloom. Wait until the hydrangea enters dormancy in the fall to cut it back.

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  1. Hydrangea. ASPCA.

  2. Hydrangea paniculata. North Carolina State University Cooperative Extension.

  3. Hydrangea paniculata 'Rensun'. Missouri Botanical Garden.