How to Grow and Care for Strawberry Vanilla™ Hydrangea

Strawberry vanilla hydrangea with bi-colored flower head of white and pink petals clustered on branches

The Spruce / Evgeniya Vlasova

Hydrangeas are known for the summer color that they afford the landscape, and strawberry vanilla hydrangea is one type that furnishes that color in style. Strawberry Vanilla is the commercial trade name for a popular hydrangea cultivar, Hydrangea paniculata 'Renhy'. This is a plant that changes as the summer wears on, so you are not stuck with one floral color. The blooms are white at first, but soon they morph to pale pink and mature to strawberry red. That color change does not happen uniformly across the flower head, however; the result is a bi-colored flower head. The pink color gradually becomes deeper, until, finally, you are left with a very attractive pinkish-red. But, for further variety, new stems with white flowers mix in with the pinkish-red of the older stems in late summer.

Strawberry Vanilla™ is normally planted as a potted nursery specimen in early fall or spring. Like most Hydrangea paniculata cultivars, it is a fast-growing plant that often achieves full size within a year.

Common Name Strawberry Vanilla™ hydrangea
Common Name Hydrangea paniculata 'Renhy' (brand name is Strawberry Vanilla)
Family Hydrangeaceae
Plant Type Deciduous shrub
Mature Size 6-7 ft. tall, 4-5 ft. wide
Sun Exposure Full
Soil Type Well-drained
Soil pH Neutral to acidic
Bloom Time Summer, fall
Flower Color White, pink
Hardiness Zones 3–8 (USDA)
Native Area Cultivar, no native range; parent species is native to Asia

Strawberry Vanilla™ Hydrangea Care

Strawberry Vanilla™ hydrangea does best when planted in well-drained soil in a full sun location. Dig a large hole, about twice the diameter of the nursery container, and plant the shrub at the same height as it was in the container (top of plant crown at ground level). Backfill, then water thoroughly. This plant will quickly grow to 5 feet in diameter, so give plenty of space between shrubs.

This is a shrub that blooms on new growth, so prune it in late winter or early spring. It usually grows best as a multi-stem shrub, but you can also create a tree-like appearance by selecting a central leader and pruning off the other stems.

Strawberry vanilla hydrangea with bi-colored flowers clustered with white and pink petals closeup

The Spruce / Evgeniya Vlasova

Strawberry vanilla hydrangeas on branches with white and pink bi-colored flower heads

The Spruce / Evgeniya Vlasova

Strawberry vanilla hydrangea on long thin stems with white and pink flower heads in between branches

The Spruce / Evgeniya Vlasova

Light

Strawberry Vanilla™ hydrangea flowers most vigorously (and with the best color) in full sun. Without at least six hours of direct sunlight daily, plants will get overly leggy with fewer blossoms. Given a choice, they would prefer to enjoy direct sun during the morning hours.

Soil

The primary soil requirement for strawberry vanilla hydrangea is good drainage—beyond that, any soil composition will suffice. This hydrangea prefers a neutral or slightly acidic pH, but isn't terribly fussy.

Water

This bush has average water needs; the standard "1 inch of water per week" rule will generally work fine for hydrangeas. Lack of water may result in fewer flowers, so be sure to water it during periods of drought in the summer and or spells of particularly hot weather.

Temperature and Humidity

Strawberry Vanilla™ hydrangea is reliably hardy in zones 4 to 8 and can survive with winter protection in zone 3. It will tolerate temperatures down to minus 30 degrees Fahrenheit. In humid climates, it may be somewhat more susceptible to fungal diseases.

Fertilizer

If your soil is poor to begin with, this plant should be fed well. The best thing to do in such instances is to amend the soil with plenty of compost yearly. If you do not mind using chemicals, you can supplement the compost with the application of a slow-release, balanced fertilizer each spring once growth has begun.

Withhold all fertilizer after late July, as this allows the shrub to move toward winter dormancy.

Types of Hydrangeas

Strawberry Vanilla™ is a unique cultivar of Hydrangea paniculata, but note that there are many other kinds of hydrangeas. The Hydrangea genus has several distinct species that are cultivated as garden plants.

  • Hydrangea paniculata: This species, which includes Strawberry Vanilla™, are often pruned into tree form, and are sometimes known as tree hydrangeas, or peegees.
  • Hydrangea macrophylla: The Latin name says it all, as this kind has big leaves. This is the species that varies the color of its flowers depending on the pH of the soil.
  • Hydrangea quercifolia: This is a type valued more for its leaves (which resemble oak leaves) than for its flowers.
  • Hydrangea arborescens: This plant is valued for its large flower heads, such as Incrediball (Hydrangea arborescens 'Abetwo').
  • Hydrangea petiolaris: This is a true vining plant, often trained on fences and trellises.

Pruning

Panicle hydrangeas such as Strawberry Vanilla™ flower on new wood that grows in the current season. For this reason, it's important to do your pruning after they have flowered, in late fall to early spring. Pruning at the wrong time (late spring or early summer) can reduce flowering if new growth is being trimmed off.

Hydrangeas should not be heavily pruned until they are quite mature, five or six years old. At this time, annual heavy pruning that cuts away up to one-third of the total growth can help keep the plant healthy and provide good air circulation to prevent fungal diseases. Regular heavy pruning also tends to create plants that produce larger, but fewer, flowers.

A badly overgrown shrub can even be chopped back to ground level; it will generally come back to full health within a single growing season.

Propagating Strawberry Vanilla™ Hydrangea

This is a trademarked, copyrighted cultivar that may not be propagated by any means. Doing so can potentially invite legal consequences. Seed propagation is not an option, either, as the flowers of this cultivar are sterile.

Potting and Repotting Strawberry Vanilla™ Hydrangea

Container culture is not common for hydrangeas, but Strawberry Vanilla™ is a relatively small cultivar that can work in a patio or deck container. Choose a pot at least 16 to 24 inches wide, with good drainage. It's best to use a frost-proof container, such as wood or plastic, as rigid clay or ceramic pots could split and shatter in below-freezing temperatures

Fill the pot with a standard commercial potting mix. Potted plants will need more frequent watering and fertilizing, but stop fertilizing in late July to allow the plant to move toward winter dormancy. Hydrangeas will need to be repotted every few years as they become root bound. Once you reach a maximum pot size, it's possible to root-prune the plants every few years, replanting them in the same container filled with new soil.

Potted plants should be over-wintered by moving them to a sheltered location.

Overwintering

Panicle hydrangeas are normally very winter hardy into zone 4, and they will usually survive nicely without any winter protection. But in zone 3, it's a good idea to water the shrubs well going into winter to prevent desiccation from cold winter winds. Covering the root zone with a good blanket of mulch or compost for the winter is also a good idea in extreme climates.

In all regions, feeding should be withheld from mid-summer onward after the flowers have appeared, as you want to avoid stimulating new growth that can be injured by cold winter winds.

Common Pests & Plant Diseases

This bush can suffer from a few different disease problems (such as bacterial wilt, blight, leaf spot, mildew, and rust), all of which can be minimized by providing plenty of space (to promote air circulation) between your Strawberry Vanilla™ hydrangea and any other plants.

Bugs such as aphids and mites can also attack it; be on the lookout for them and, upon detection, spray immediately with neem oil organic insecticide.

How to Get Strawberry Vanilla™ Hydrangea to Bloom

This shrub normally begins blooming in midsummer, with large flower panicles that begin white, then gradually transition through pink to pinkish red by fall. The strawberry red color will maintain for three to four weeks before turning brown—though the browned flower heads are also attractive. Larger blooms can be created if you prune off all but six to 10 of the main stems.

Failure to bloom is often traced to a lack of water, poor soil, or a lack of adequate sunlight. Regular water and fertilizer are essential for good blooming. There are other possible reasons why these plants withhold blooms:

  • Plants that are getting too much nitrogen fertilizer sometimes withhold flowers as they put most of their energy into foliage production. This can happen when a shrub is surrounded by turf grass that is regularly fertilized.
  • Improper pruning—removing new growth in the current growing season—will also reduce flowering. These plants flower on new growth so should be pruned during their dormant period in winter or early spring.

Common Problems With Strawberry Vanilla™ Hydrangea

Panicle hydrangeas are generally quite trouble-free, but some growers are annoyed by the way the heavy flowers cause the stems to droop. This can be remedied by making sure the plant has plenty of sunlight and keeping it closely pruned to prevent it from getting too tall.

FAQ
  • How should I use this shrub in the landscape?

    Panicle hydrangeas are a good choice wherever you want a shrub that provides color in the mid-summer to fall season when most flowering shrubs have already faded. They can work well when massed in a group in a shrub border or open woodland garden, but also make good specimen shrubs. They can also work in hedge applications, or as foundation plantings.



  • Can I grow Strawberry Vanilla™ hydrangeas near the roadside?

    Strawberry Vanilla™ hydrangea tolerates air pollution well. This fact makes it not only a good shrub to grow in the city, but also a candidate for shrub beds located close to the road.

  • How long does this plant live?

    It's not uncommon for panicle hydrangeas to reach 50 years if they are well cared for.