Sioux crape myrtle

Sun

Full sun, with at least 6 hours of direct sunlight daily; choose a warm, sheltered position in cooler regions.

Water

Water regularly while establishing; once established, it tolerates dry spells but flowers better with occasional deep watering during prolonged drought.

Soil

Well-drained loam, clay or sandy soil; tolerates a range of pH levels but dislikes waterlogged ground.

Height

12-20 ft (3.7-6.1 m)

Spread

10-15 ft (3-4.6 m)

Flowers

Clusters of clear pink, crinkled flowers from midsummer into early autumn; timing and duration depend on summer warmth.

Foliage

Small oval leaves emerge green, deepen through summer and turn orange to red in autumn; older stems develop smooth, peeling bark.

Growth

Moderate to fast in warm climates.

Care needed

Low

• Pollinators
• Deer resistant
• Drought tolerant
• Heat tolerant
• Disease resistant
• 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

   7 ft (2 m)

2. After 1 year

   7 ft (2.2 m)

3. After 2 years

   8 ft (2.4 m)

4. After 3 years

   8 ft (2.5 m)

5. After 5 years

   10 ft (2.9 m)

About 16 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

Safe

Growth rate

Fast

• Water deeply through the first two growing seasons whenever the root zone begins to dry.
• Apply 2-3 in (5-8 cm) of organic mulch, keeping it away from the trunk.
• Feed lightly in spring only if growth is weak or the soil is poor; excess nitrogen encourages leaves rather than flowers.
• Keep lawn equipment away from the thin bark and avoid planting where the trunk will be repeatedly bumped.
• Leave enough space for the mature crown rather than relying on hard annual pruning.

Pruning. In late winter or early spring, remove dead, damaged and crossing branches, along with unwanted basal shoots. If training a small tree, retain a few well-spaced trunks and gradually remove lower branches; do not top or cut the main stems back to stubs.

Late winter

Check branch structure and remove dead or crossing wood before new growth begins.

Spring

Plant in cooler climates once severe frost has passed; water thoroughly and mulch.

Late spring

Check for new growth before judging winter damage; crape myrtles often leaf out late.

Summer

Water young trees deeply during dry spells and inspect stems and leaf undersides for pests.

Late summer

Avoid nitrogen feeding that could encourage soft growth before winter.

Autumn

Enjoy the leaf colour, then clear fallen leaves if disease has been present.

• Use as a small specimen tree near a patio, allowing room for its spreading crown.
• Plant against a dark evergreen backdrop to show off the pink flowers and pale bark.
• Combine with ornamental grasses and sun-loving perennials for a long-season border.
• Train as a multi-stemmed tree in an open lawn or courtyard where its winter branch structure can be seen.

Garden styles it suits: Southern, Modern courtyard, Traditional, Cottage garden, Autumn colour and Winter interest.

Plant it with: Catmint, Purple coneflower, Black-eyed Susan, Switchgrass, Salvia and Liriope.

Wildlife: Flowers provide pollen for bees and other insects, although they offer little or no nectar. The branches provide perching and some cover for small birds.

• Crape myrtle bark scale: white, felted insects on stems can cause black sooty mould; confirm identification and seek locally approved treatment advice, especially for established infestations.
• Aphids: sticky honeydew and sooty mould may develop on leaves; wash off small colonies with water and conserve ladybirds and other predators.
• Powdery mildew: Sioux is resistant, not immune; provide full sun and airflow, and avoid excessive nitrogen feeding.
• Poor flowering or winter dieback: cool summers, shade or severe cold can limit performance; use the warmest sunny site available and wait for new growth before removing apparently dead stems.

Not known to be toxic to people, cats, dogs or horses; no part is generally recognised as poisonous. It is an ornamental plant, not a food crop.

• Rose of Sharon (Hibiscus syriacus)

  Has larger, often lobed leaves and individual hibiscus-shaped flowers with a prominent central staminal column, rather than clusters of small crinkled flowers.

• Chaste tree (Vitex agnus-castus)

  Has aromatic leaves divided into narrow leaflets and slender spikes of usually violet-blue flowers; Sioux has simple oval leaves and broad pink flower clusters.

Lagerstroemia honours Swedish merchant and natural-history patron Magnus von Lagerström, while 'Sioux' follows the US National Arboretum's practice of naming its hybrid crape myrtles for Native American peoples.

Propagation. Root softwood cuttings in late spring or early summer, or semi-ripe cuttings later in summer. Seedlings will not reliably retain the characteristics of 'Sioux'.

Accepted botanical name

Lagerstroemia

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