How to Grow Shooting Star Hydrangea

This popular holiday shrub has eye-catching white petals

Shooting Star Hydrangea against black background

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Shooting Star Hydrangea are often sold in containers as an alternative to the Poinsettia during the holiday season. They feature eye-catching white star-shaped double flowers that turn pale green after a month or two.

These deciduous shrub-like plants can grow to be up to 5 foot tall, and, if you live in a temperate climate, they can be planted outdoors too.

Because these plants are often forced to bloom to be sold during the winter season, it means they can be stressed when they arrive with you. As a result, you'll need to provide them with nurturing care to ensure their survival, particularly if you plan to repot them outside.

This unusual lace cap variety of Hydrangea is a cultivar often referred to as Hydrangea macrophylla "Hanabi" or "Fireworks". Although they look markedly different from the traditional bigleaf Hydrangea, they have similar care requirements.

Botanical Name Hydrangea macrophylla "Hanabi"
Common Name Hydrangea 'Shooting Star'
Plant Type Perennial deciduous shrub
Mature Size Up to 5 foot
Sun Exposure Full Sun/ Partial Shade
Soil Type Tolerates a wide range but must be moist and well-drained
Soil pH Preference for around 6.5 to 7
Bloom Time Late summer to fall
Flower Color White
Hardiness Zones 5 to 9
Native Area Asia and United States Gulf Coast

How to Grow Shooting Star Hydrangea

These plants grow well in containers indoors with the right care and attention. With a little more attentiveness, providing the climate is mild enough, they can also grow outdoors.

They don't do well in cold, freezing conditions and should be brought inside or covered over if frost is expected. This Hydrangea species prefers a shady position with only partial sun exposure. Not a drought-tolerant plant, Shooting Star Hydrangeas need well-drained, moist soil conditions.

Light

Shooting Star Hydrangeas kept in the garden do best with a partial sun position. They don't appreciate continuous direct sun and benefit from shade in the afternoon.

Soil

A slightly acidic, well-draining and irrigated soil works well for this plant. When planted outdoors, adding a few inches of organic mulch can help to retain the moisture that Shooting Star Hydrangeas prefer.

Although it prefers moisture, make sure you don't allow the soil to become water-logged or that you press the mulch up against the stem.

Water

Your Shooting Star Hydrangea will appreciate regular watering. In indoor pots, once the very top layer of soil is feeling dry, evenly water until you see the water draining from the bottom of the container.

Even in the colder months when the plant is dormant, you shouldn't let the soil dry out completely when kept indoors.

Outdoors, during the dry months, thorough watering once a week is recommended.

Temperature and Humidity

When grown outdoors, this Hydrangea species needs mild weather conditions. Exceptionally hot, sunny conditions can be too much for this plant, and it doesn't cope with a hard frost either.

Fertilizer

Feeding your Shooting Star Hydrangea with a slow-release fertilizer in the spring as new growth is starting can encourage a full bloom.

Propagating Shooting Star Hydrangea

It's possible to propagate this plant by taking softwood cuttings through the summer months. Selecting around four to six inches from a new growth stem is preferable. Keep the top two leaves on the cutting and then dip in rooting hormone.

Pot the cutting in rich, moist potting soil and cover it over with a bag. Make sure you position it out of direct sunlight and that the soil is kept damp. You can expect to wait up to four weeks for roots to be established.

Toxicity of Shooting Star Hydrangea

Although all parts of the Shooting Star Hydrangea are toxic, a lot would have to be ingested for it to cause any problems. This isn't one you have to panic about and remove from your garden

Hydrangeas contain cyanogenic glycoside. Although cyanide poisoning would be exceptionally rare, it can still lead to people, dogs, cats and even horses being ill if they consume enough.

Shooting Star Hydrangea: Symptoms of Poisoning

Even if a large amount of Hydrangea was consumed, it would most likely result in a gastric upset rather than anything more serious.

Vomiting, diarrhea and lethargy are common symptoms.

Pruning

Deadheading flowers past their best and pruning back only spent branches after the blooming season will help to encourage new, healthy growth the next season.

However, this plant doesn't need harsh cutting back as some shrubs do. Over pruning can result in overly flexible stems.

Being Grown in Containers

This plant is commonly grown in containers and does well in them in the right indoor or outdoor setting.

Because of the level of stress these plants can be under after having been forced to bloom out of season, it can be a good idea to immediately repot them in a new container. Select a large pot—remember these plants can grow to be five feet tall. Make sure you choose a rich, high-quality potting soil. You can transfer them out to the garden in early spring to allow them to flourish in a suitable partial shade position.

If you're keeping the plant in a container outdoors, it's a good idea to bring it indoors for fall and winter when the temperatures drop, especially if you're expecting a frost.

Common Diseases

Leaf Spot Disease, which results in brown or purple marks developing, can be common in Hydrangea species, and the Shooting Star is no exception. It can impact on flowering ability and cause leaf drop.

It's particularly common if your plant is exposed to heavy rainfall during the summer months or if you regularly water from above.

Make sure you carefully remove all affected leaves to minimize the chance of reinfection.

If the case is severe, you can apply a fungicide once a fortnight. The best ones are those containing the active ingredient mancozeb or chlorothalonil.