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Threlkeldia spp.
bonefruit
Southern Australia, coastal and saline sites
Overview
Threlkeldia is a small genus of two succulent-leaved species in the family Amaranthaceae, native to coastal and saline habitats across southern Australia. Plants are low, sprawling subshrubs 4-24 inches (10-60 cm) tall and 1-3 feet (0.3-0.9 m) wide, with fleshy, cylindrical, blue-green to grey-green leaves that often flush red in strong sun or salt stress. The widespread species, T. diffusa, the coast bonefruit, forms loose mats over dunes, salt flats, and clay pans. Tiny flowers sit in the leaf axils and are followed by small, succulent, often reddish fruits that hold a single hard seed, the bone that gives the genus its common name. As a salt-tolerant halophyte, Threlkeldia withstands saline soil, salt spray, drought, and poor, alkaline ground that excludes most other plants. It needs sharp drainage and full sun and rots in heavy, wet, shaded conditions. Frost tolerance is limited, so the genus suits warm coastal and semi-arid climates. The sprawling growth can spread untidily without occasional trimming.
Native Range
Threlkeldia is native to southern Australia, on coasts and inland saline sites across Western Australia, South Australia, Victoria, New South Wales, and Tasmania. It grows on dunes, salt flats, samphire margins, and clay pans.Suggested Uses
Used for coastal stabilisation, saline and dry-garden plantings, and ground cover on exposed, salty banks. Suited to seaside and semi-arid sites where salt and drought limit other plants.How to Identify
Appearance
Size & Dimensions
Height4" - 2'
Width/Spread1' - 3'
Reaches mature size in approximately 2 years
Bloom Information
Detailed Descriptions
Flower Description
green to yellowFoliage Description
blue-green to grey-green, reddening in sunGrowing Conditions
Sun Requirements
Requires 6-10 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
Care & Maintenance
Care Guide
Grow in full sun on light, sharply drained sandy, rocky, or alkaline soil, including saline and coastal sites. Water sparingly, as plants tolerate drought and salt and rot in heavy, wet ground. No feeding is needed on poor soils. Trim sprawling stems to keep growth contained. Frost tolerance is limited, so the genus suits warm, frost-free or near-frost-free climates.Pruning
Trim straggly or spreading stems at any time to keep plants compact. Plants tolerate cutting back into firm growth. Remove dead or frost-damaged stems as they appear.Container Growing
Suitable for container growing
Minimum container size: 3 gallons