Hino Crimson azalea

Sun

Partial shade, ideally morning sun and afternoon shade. Tolerates more sun in cool climates if the roots stay moist; avoid hot, exposed sites.

Water

Keep the shallow root zone evenly moist but never waterlogged. Water during dry spells, especially through the first two growing seasons and when growing in containers.

Soil

Acidic, humus-rich, well-drained soil, ideally pH 4.5-6.0. In alkaline ground, use a container filled with ericaceous potting mix rather than trying to acidify the whole bed.

Height

2-4 ft (0.6-1.2 m)

Spread

3-5 ft (0.9-1.5 m)

Flowers

Crimson-red flowers in early to mid-spring; timing varies with climate.

Foliage

Evergreen. Small, glossy, dark green leaves often turn bronze or reddish in cold weather. Some leaves may drop in exposed or colder gardens.

Growth

Slow to moderate.

Care needed

Medium

• Pollinators
• 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

   1.8 ft (0.56 m)

3. After 2 years

   2 ft (0.62 m)

4. After 3 years

   2.2 ft (0.68 m)

5. After 5 years

   2.7 ft (0.81 m)

About 7 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

Slow

• Plant with the top of the root ball level with, or slightly above, the surrounding soil; do not bury the crown.
• Water deeply when the surface soil begins to dry, using rainwater where tap water is very hard.
• Apply 2-3 in (5-8 cm) of leaf mould or fine pine bark over the root zone, keeping it clear of the stems.
• If growth is weak, apply an acid-loving shrub fertiliser at the label rate in spring; avoid late-season feeding.
• Avoid digging or hoeing around the shallow roots, and shelter plants from drying winter winds.

Pruning. Prune only as needed immediately after flowering, shortening stray shoots to a leafy side shoot and removing dead wood. Avoid routine summer or autumn clipping, which removes the following spring's flower buds.

Early spring

Check soil moisture and winter damage; feed lightly if growth or soil conditions justify it.

Spring

Plant into prepared acidic soil or an ericaceous container mix, then water thoroughly.

Late spring

After flowering, trim only where needed to maintain the shape.

Summer

Water during dry weather and check leaf undersides for lace bugs.

Autumn

Refresh mulch and water during dry spells before the ground freezes.

Winter

Protect exposed container roots from prolonged freezing and check that drainage holes remain clear.

• Plant in small groups along a lightly shaded woodland edge for a concentrated spring display.
• Use beneath high-canopied trees alongside ferns and hostas, avoiding places with severe root competition.
• Place near a path or entrance where its low, rounded outline will not obscure views.
• Grow in a broad container with ericaceous potting mix where garden soil is alkaline.

Garden styles it suits: Japanese, Woodland, Traditional, Cottage garden, Pacific Northwest woodland and Small-space.

Plant it with: Japanese pieris, Japanese maple, Camellia, Hosta, Japanese painted fern and Lenten rose.

Wildlife: Flowers may attract bees, although their value varies with local insects and conditions. The dense foliage provides modest shelter for small garden animals.

• Azalea lace bugs cause pale stippling on upper leaf surfaces and dark specks beneath. Reduce drought stress, avoid hot exposed positions, and treat leaf undersides with an insecticidal soap labelled for the pest if needed.
• Phytophthora root rot causes wilting and root decay in wet soil. Improve drainage before planting and remove badly affected plants; extra watering makes the problem worse.
• Yellow leaves with green veins often indicate iron deficiency caused by alkaline soil or water. Check pH, use rainwater where practical, and move container plants into fresh ericaceous mix if needed.
• Brown flower buds or scorched leaves can follow frost and drying winds. Choose a sheltered position, maintain soil moisture and cover flowering plants temporarily during forecast late frosts.

All parts contain grayanotoxins and are poisonous to people, cats, dogs and horses if eaten. Ingestion can cause vomiting, weakness, dangerous heart disturbances and, in severe cases, death; seek urgent medical or veterinary advice.

• PJM rhododendron (Rhododendron PJM Group)

  PJM rhododendrons usually have lavender-pink flowers in rounded clusters and larger, leathery leaves; Hino Crimson has smaller leaves and crimson-red flowers.

• Japanese deciduous azalea (Rhododendron molle subsp. japonicum)

  This azalea loses its leaves in winter and usually bears larger orange to orange-red flowers. Hino Crimson retains much of its smaller foliage and forms a more compact mound.

Rhododendron comes from the Greek words for 'rose' and 'tree', while 'Crimson' describes this cultivar's red flowers.

Propagation. Take semi-ripe cuttings in summer and root them in a moist, free-draining acidic medium under high humidity. Low branches can also be layered; seed will not reliably reproduce this cultivar.

Accepted botanical name

Rhododendron

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