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Sida fallax

Ilima

Malvaceae Hawaii and the tropical Pacific

Attracts Pollinators Attracts Butterflies Drought Tolerant Container Friendly

SunFull Sun

WaterVery Low · drought-tolerant

HardinessZones 9–11

Overview

Sida fallax is a variable evergreen shrub ranging from a prostrate coastal mat 6-12 inches (15-30 cm) high and 3-6 feet (0.9-1.8 m) across to an erect inland form 3-10 feet (0.9-3 m) tall. Stems and leaves carry dense stellate hairs that give the foliage a gray-green velvety surface. Leaves are ovate to heart-shaped, 0.5-2 inches (1.3-5 cm) long, with crenate margins and a blunt tip. Flowers are five-petalled, 0.75-1 inch (2-2.5 cm) across, and run from clear yellow through orange to reddish-orange depending on population; each opens in the morning and closes by mid-afternoon, so the display renews daily rather than persisting. Fruit is a flattened schizocarp splitting into 5-9 one-seeded segments. Flowering continues year-round in frost-free climates. Coastal forms tolerate salt spray, calcareous sand, and prolonged drought, while upland forms occupy dry shrubland to 2,000 feet (600 m). Plants are short-lived at 4-8 years and go woody and sparse at the base without cutting back. Between 500 and 1,000 flowers go into a single lei ilima, which is why the flowers are gathered across several mornings.

Native Range

Sida fallax is indigenous to Hawaii and occurs naturally across the tropical Pacific, from southern China and the Ryukyu Islands east through Micronesia and Polynesia. In Hawaii it grows on all main islands from coastal strand and dune up to dry shrubland at 2,000 feet (600 m). It was designated the island flower of Oahu.

Suggested Uses

Grown as a groundcover, low hedge, and dune stabilizer in coastal gardens at spacings of 2-4 feet (0.6-1.2 m). Planted in Hawaiian dry-forest and coastal restoration alongside Scaevola taccada and Heliotropium anomalum. Flowers are strung into lei ilima, and plants are grown in 5 gallon (19 L) containers on walls and terraces where the prostrate form trails over the edge.

How to Identify

Foliage carries the primary character: small ovate to heart-shaped leaves 0.5-2 inches (1.3-5 cm) long, crenate at the margin, and coated on both surfaces with stellate hairs that leave a soft gray-green nap. Flowers sit singly or in small clusters in the leaf axils, five-petalled and yellow to orange, closing by early afternoon. The fruit is a ribbed disc that breaks into 5-9 wedge-shaped segments. Prostrate coastal plants root at the nodes where stems contact sand.

Appearance

Size & Dimensions

Height6" - 10'

Width/Spread3' - 8'

Reaches mature size in approximately 3 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~52 weeks

Spring Summer Fall Winter

Flowering continues throughout the year in frost-free conditions, with peak flushes following rain. Each flower opens shortly after sunrise and closes by mid-afternoon, lasting a single day. A mature plant carries 10-50 open flowers on a peak morning and produces continuously for months. Seed ripens 4-6 weeks after flowering and the mericarps drop as the calyx dries.

Detailed Descriptions

Flower Description

Yellow to orange, occasionally reddish-orange

Foliage Description

Gray-green and velvety

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 8.5(Alkaline)

357912

Soil Types

sand rocky loam

Drainagewell drained

Water & Climate

Water Needs

Very Low

Frost Tolerance

tender

Time to Maturity

1-2 years to flowering size

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Sida fallax grows in full sun on sharply drained sand, coral rubble, cinder, or rocky loam at pH 6.0-8.5, and coastal forms handle direct salt spray. Established plants need no irrigation where rainfall reaches 15 inches (380 mm) a year or more, and root rot follows sustained wet soil or heavy shade. Hardiness runs to USDA zones 9-11, with damage below 30F (-1C). Fertilizer is unnecessary on native substrate and pushes soft growth that flops. Whitefly, spider mite, and Chinese rose beetle feed on the foliage in humid gardens, and plants in still air develop powdery mildew. Plants are replaced every 4-8 years from seed or from softwood cuttings taken in spring.

Pruning

Plants are sheared by about one third in early spring to keep the base clothed in growth, since untrimmed stems lose their lower leaves within 2-3 years. Prostrate forms are cut back at the perimeter to hold them within 3-6 feet (0.9-1.8 m). Cuts into bare wood over 0.5 inch (1.3 cm) thick regenerate slowly. Light trimming is repeated at any time of year in the tropics.

Pruning Schedule

early spring