How to Grow and Care for Vanilla Strawberry™ Hydrangea

Hydrangeas are known for the summer color they bring to a landscape, and the Vanilla Strawberry hydrangea furnishes that color in style. Vanilla Strawberry is the commercial trade name for a popular hydrangea cultivar, Hydrangea paniculata 'Renhy'.

The blooms on this hydrangea change color as the summer wears on. The blooms are pure white at first, but soon they begin to transition to a pale pink and mature to a deep strawberry red color. That color change does not happen uniformly across the flower head; the result is usually a bi-colored flower head. The pink color gradually becomes deeper deeper pink and finally a very attractive dark shade of strawberry red. But, for further variety, some new stems with white flowers mix in with the pinkish-red of the older stems in late summer.

Vanilla Strawberry is usually 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.

Vanilla Strawberry Hydrangea Care

A Vanilla Strawberry hydrangea does best when planted in well-drained soil in a full sun location with six to eight hours of direct sun each day. Dig a large hole, about twice the diameter of the nursery container, and plant the shrub at the same level as it was growing in the container (top of plant crown at ground level). Backfill with soil, then water thoroughly. This plant will grow to five feet in diameter, so provide plenty of space between plants.

Panicle hydrangeas bloom on new stem growth, so prune your Vanilla Strawberry hydrangea in late winter or early spring before new growth begins. It usually grows best as a multi-stem shrub, but you can also create a tree-like appearance by selecting a straight central leader stem and removing the other side stems.

Light

Vanilla Strawberry hydrangea produces flowers most vigorously (and with the best color) in full sun, six to eight hours per day. With less than six hours of direct sunlight daily, plants will become overly leggy with fewer blossoms. Given a choice, they prefer to enjoy direct sun during the morning hours.

Soil

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

Water

This hydrangea has average water needs; the standard one inch of water per week rule will generally be sufficient. Lack of water might result in fewer flowers, so be sure to water during periods of drought in the summer and or spells of particularly hot weather.

Temperature and Humidity

Vanilla Strawberry hydrangea is reliably hardy in USDA cold hardiness 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 might be somewhat more susceptible to fungal diseases.

Fertilizer

If soil is poor, provide nutrients to this shrub regularly. The best method is to amend the soil with plenty of compost every year. If you're not opposed to using chemical fertilizers, you can supplement the compost with an application of a slow-release, balanced fertilizer each spring once growth has begun.

Withhold all fertilizer after late July to allow the shrub to move toward winter dormancy.

Types of Hydrangeas

Vanilla Strawberry 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 Vanilla Strawbery, are often pruned into tree form and are sometimes known as tree hydrangeas, or peegees.
• Hydrangea macrophylla: The botanical name says it all, as this kind of hydrangea has big leaves and one of its common names is mophead hydrangea. This is the species where soil pH controls the color of the flowers. Acidic soil produces blue blooms, and alkaline soil produces pink blooms.
  
• Hydrangea quercifolia: Also known as the oakleaf hydrangea. 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 and climbing hydrangea often trained on fences and trellises.

Pruning

Panicle hydrangeas such as Vanilla Strawberry flower on the current season's new stem growth. It sets its bud in springtime on new stems for summer flowering. For this reason, it's important to do your pruning in late fall, winter, or very early spring before new stem growth starts. Pruning at the wrong time (late spring or early summer) will reduce flowering because you might remove the new stems on which flower buds have formed.

Annual heavy pruning that removes up to one-third of the total growth can help keep the plant healthy by creating good branching and enable good air circulation to prevent fungal diseases. Regular heavy pruning also tends to create plants that produce larger, but fewer, flowers.

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

Propagating Vanilla Strawberry Hydrangea

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

Potting and Repotting Vanilla Strawberry Hydrangea

Container culture is not common for hydrangeas, but Vanilla Strawberry is a relatively small cultivar that can be grown in a large patio or deck container. Choose a pot at least 16 to 24 inches wide with drainage holes. 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 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.

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

Overwintering

Panicle hydrangeas are normally very winter hardy to USDA cold hardiness 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 few-inches-thick blanket of mulch or compost for the winter is also a good idea in extreme climates.

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

Common Pests & Plant Diseases

This hydrangea can suffer from a few different diseases (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 hydrangea and any other plants.

Insects 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 Vanilla Strawbery Hydrangea to Bloom

This shrub normally begins blooming in midsummer with large flower panicles that begin white, then gradually transition through pink to strawberry red by fall. The dark color will last for three to four weeks before turning paper-brown—though the browned flower heads are also attractive and serve as winter interest. Larger blooms can be created if you prune off all but six to ten 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. Other possible reasons why these plants don't bloom are:

• Plants that receive too much nitrogen fertilizer sometimes don't flower because they put most of their energy into producing foliage. This can happen when a shrub is surrounded by turf grass that is regularly fertilized.
• Improper pruning—removing new stem growth in the late spring or summer—will also reduce flowering. These plants set their buds and flower on new stem growth so should be pruned during their dormant period in winter or very early spring.

Common Problems With Vanilla Strawberry 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.

From: thespruce