Royal palm

Sun

Full sun; young palms tolerate partial shade.

Water

Moderate to high; water deeply during dry weather. Established palms tolerate brief dry spells but grow best with consistent moisture.

Soil

Deep, fertile soil that holds moisture without remaining stagnant; tolerates sandy and limestone soils if adequately watered and fed.

Height

50-80 ft (15-24 m), occasionally taller

Spread

15-25 ft (4.6-7.6 m)

Flowers

Branched clusters of small creamy-white flowers appear below the crownshaft, mainly in warm months; timing varies with climate.

Foliage

Evergreen. Large, arching, feather-shaped green fronds, often 10-15 ft (3-4.6 m) long, with leaflets arranged in several planes.

Growth

Moderate to fast in warm, moist conditions.

Care needed

Medium

• Pollinators
• Heat tolerant
• Wildlife

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

Difficulty

Hard

Toughness

Needs looking after

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

1. Planting day

   8 ft (2.3 m)

2. After 1 year

   11 ft (3.4 m)

3. After 2 years

   15 ft (4.5 m)

4. After 3 years

   18 ft (5.6 m)

5. After 5 years

   25 ft (7.7 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

Native to

the US

Growth rate

Fast

• Plant in warm weather with the root ball at its original depth; do not bury the trunk.
• Water newly planted palms regularly, keeping the root ball moist but not continuously saturated.
• During active growth, use a slow-release palm fertiliser containing potassium, magnesium and micronutrients, following the label.
• Apply a 2-3 in (5-8 cm) mulch layer over the root area, keeping it clear of the trunk.
• Keep the area beneath the crown away from seating, play spaces and parked cars because entire heavy fronds fall naturally.

Pruning. This palm sheds its own old fronds and normally needs no leaf pruning; never remove healthy green fronds or cut the growing point. Have a qualified arborist remove hazardous hanging material or unwanted flower and fruit stalks when necessary.

Spring

Apply palm fertiliser as growth resumes, following local recommendations and the product label.

Late spring

Plant or transplant once the soil is warm, allowing ample room for the mature crown and falling fronds.

Summer

Water deeply during rainless periods and check new foliage for stippling or distortion.

Late summer

Inspect older leaves for nutrient-deficiency symptoms; adjust the feeding programme rather than cutting off affected green leaves.

Autumn

Collect fallen fruit near paths and check for loose or hanging fronds before stormy weather.

Winter

Reduce irrigation when growth slows, but do not let newly planted root balls dry out; protect small specimens from exceptional cold.

• Plant in widely spaced rows along broad drives to create a formal avenue.
• Use as a single vertical focal point in a large tropical lawn.
• Group several palms with lower tropical foliage for a layered, resort-style landscape.
• Frame distant views or large buildings, keeping the crowns and falling-frond zones clear of occupied areas.

Garden styles it suits: Architectural minimal, Formal, Modern tropical, Luxury resort, Florida subtropical and Caribbean.

Plant it with: Croton, Hibiscus, Ixora, Philodendron, Shell ginger and Bird of paradise.

Wildlife: Flowers attract bees and other insects, and ripe fruits feed birds and some mammals. Fruit-eating wildlife may disperse seeds beyond the garden.

• Royal palm bugs cause pale stippling and damaged young foliage. Seek a diagnosis before treatment; large palms require professional assessment and equipment.
• Potassium deficiency causes spotting and premature death of older fronds. Use a balanced palm fertiliser with adequate potassium and magnesium; retain living affected leaves.
• Manganese deficiency can produce small, frizzled new leaves, especially in alkaline soils. Confirm the cause and apply an appropriate manganese treatment; ordinary magnesium supplements will not fix it.
• Ganoderma butt rot can cause decline and a shelf-like fungal growth at the trunk base. There is no cure; have the palm assessed and removed if affected, and avoid replanting another palm in the same spot.

Not known to be toxic to people, cats, dogs or horses, although specific safety information is limited and the fruit should not be treated as food. Fallen fruits can be swallowed by pets, and heavy falling fronds are a more significant physical hazard.

• Caribbean royal palm (Roystonea oleracea)

  Usually has a more upright crown, with most leaves held at or above horizontal; royal palm commonly has conspicuously drooping lower fronds.

• Alexandra palm (Archontophoenix alexandrae)

  Has a much slimmer, distinctly ringed trunk and leaflets with silvery undersides, rather than the royal palm's massive, smooth pale trunk.

• Foxtail palm (Wodyetia bifurcata)

  Has densely bushy, foxtail-like fronds and remains substantially shorter, with a slimmer trunk.

Roystonea honours the American engineer Roy Stone, while regia means royal, referring to the palm's stately appearance.

Propagation. Grow from fresh ripe seed. Remove the fruit pulp, clean the seed and sow in a moist, free-draining medium at about 77-86°F (25-30°C); germination can take several weeks to several months.

Accepted botanical name

Roystonea regia

In the US and Canada

Native in the lower 48 states. Introduced in Pacific Basin, Puerto Rico and US Virgin Islands.

Native range

Bahamas, Belize, Cayman Is., Cuba, Dominican Republic, Florida, Haiti, Honduras, Mexico Gulf and Mexico Southeast.

Measured

Average height 3000 cm.

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