BloomStruck hydrangea

Sun

Morning sun and afternoon shade; tolerates more sun in cool climates if the soil stays moist. Avoid strong afternoon sun in hot regions.

Water

Keep the root zone evenly moist but not waterlogged. Water deeply during dry spells; containers need checking more often.

Soil

Moist, well-drained soil enriched with organic matter. Acidic soil with available aluminium encourages blue-purple flowers; less acidic soil generally produces pink flowers.

Height

3-4 ft (0.9-1.2 m)

Spread

4-5 ft (1.2-1.5 m)

Flowers

Summer into early autumn, with repeat flowering depending on climate and growing conditions; rounded pink, purple or blue-purple flower heads, influenced by soil chemistry.

Foliage

Broad, toothed, dark green leaves with reddish petioles and often reddish veins; stems are red-purple.

Growth

Moderate

Care needed

Medium

• Heat tolerant
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   2 ft (0.61 m)

3. After 2 years

   2.4 ft (0.72 m)

4. After 3 years

   2.7 ft (0.83 m)

5. After 5 years

   3 ft (1.1 m)

   full size

About 5 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Growth rate

Moderate

• Water at soil level when the upper soil begins to dry; do not leave the roots standing in water.
• Apply 2-3 in (5-8 cm) of organic mulch in spring, keeping it clear of the stem bases.
• Feed lightly in spring with a balanced shrub fertiliser according to its label; avoid heavy nitrogen feeding and late-season applications.
• Shelter from drying winds and frost pockets. Although BloomStruck is sold for colder zones, the range given here reflects dependable species hardiness; winter survival does not guarantee surviving flower buds.
• Test the soil before trying to change flower colour, and use only labelled hydrangea colour treatments at the recommended rate.

Pruning. In spring, wait until buds open before removing dead stem tips, cutting back to healthy growth. Otherwise prune lightly after the first flush of flowers; avoid cutting the whole shrub down, which removes the older wood that carries early blooms.

Early spring

Check soil moisture and apply a light shrub feed as growth begins.

Spring

Once buds open, remove confirmed dead wood and renew the mulch.

Late spring

Protect tender new growth with horticultural fleece if a late frost is forecast.

Summer

Water deeply during dry weather, checking container-grown plants frequently.

After the first flowering flush

Remove spent heads just above a healthy pair of leaves if desired, keeping pruning light.

Autumn

Leave later flower heads for winter interest and stop feeding.

Winter

In cold areas, protect the crown with mulch and shelter containers from severe freezing.

• Plant in small groups along a partly shaded border for a broad band of summer colour.
• Combine with hostas and ferns beneath high, open tree canopies where roots have adequate moisture.
• Use as a low, informal hedge beside a path, allowing room for its mature spread.
• Grow in a large container on a sheltered patio, with reliable watering and good drainage.
• Place among spring-flowering shrubs to carry the display into summer.

Garden styles it suits: Cottage garden, English country, Woodland, Romantic rose garden, Hamptons and Pastel border.

Plant it with: Hostas, Japanese painted ferns, Astilbes, Coral bells, Japanese forest grass and Camellias.

Wildlife: The showy mophead consists mainly of sterile florets and offers less pollen and nectar than lacecap hydrangeas. Its dense foliage provides some shelter for small garden animals.

• Few flowers: winter injury, late frost or hard pruning can remove older flower buds. Provide shelter, protect emerging growth and retain healthy stems.
• Wilting or scorched leaves: check soil moisture before watering; dry roots need a deep soak, while repeated afternoon wilt in moist soil calls for more shade.
• Powdery mildew or leaf spots: improve airflow, water at soil level and remove fallen affected leaves; avoid crowding the shrub.
• Yellow leaves with green veins: alkaline soil can cause iron deficiency. Test soil pH, use a suitable chelated iron treatment if needed, or grow in a container with an acidic growing medium.

Toxic if eaten by cats, dogs, horses or people. All parts contain cyanogenic compounds, particularly the leaves and flower buds; ingestion usually causes digestive upset, while serious poisoning is uncommon but possible after substantial consumption. Keep clippings away from pets and livestock.

• The Original Endless Summer hydrangea (Hydrangea macrophylla 'Bailmer')

  Also a reblooming mophead with soil-dependent flower colour, but BloomStruck typically has more conspicuous red-purple stems and reddish leaf stalks. A nursery label is the most reliable distinction.

• Lacecap hydrangea (Hydrangea macrophylla, lacecap cultivars)

  Lacecaps have flattened heads of small fertile flowers surrounded by larger showy florets; BloomStruck has rounded mopheads.

• Annabelle hydrangea (Hydrangea arborescens 'Annabelle')

  Annabelle has white flower heads that age green rather than turning pink or blue with soil chemistry, and flowers on the current season's growth.

Hydrangea comes from Greek words meaning water vessel, referring to the seed capsules, while macrophylla means large-leaved.

Propagation. Softwood cuttings taken in late spring or early summer can reproduce the cultivar; seedlings will not reliably come true. This is a protected cultivar in some countries, so check local plant breeders' rights or patent restrictions before propagating.

Accepted botanical name

Hydrangea macrophylla

Native range

Japan and Kazan-retto.

Measured

Soil pH 4.5 to 8. Average height 150 cm.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.