Screw Pine Pandanus utilis Red Edge

The red margin on Pandanus utilis Red Edge is not only colour. Every leaf edge and the underside midrib carry a row of small hooked red spines, set against broad, stiff, blue green blades held in tight spirals on candelabra stems. Underneath, prop roots push out and lift the trunk clear of the ground, which is the look most buyers are after. It is a coastal architectural plant for beds that are looked at rather than walked through, in courtyards, resort frontages and feature planting near water.

Blue leaves, red spined margins

Salt wind, sand and reflected heat are all within its range, and it asks for little water once established, but it wants full sun, warmth and free draining ground. Cold, heavy soil that stays wet through winter will see it decline. The failure mode here is not climate, though, it is the bed. Prop roots spread outward from the base and keep coming as the plant ages, and a plant set against a paving edge, a pool coping or a narrow garden strip will lift and shove that edge aside within a few years. Give it a wide bed from the start and set it back from the hard edge rather than centring it in a strip. The same applies to services and irrigation lines running close to the base. Growth is slow, so plan the bed for the plant you will have in a decade rather than the one you are installing, and mound the position if drainage is doubtful. Feeding and watering will not rescue a bad position, so settle the drainage and the clearances at planting rather than after the first pavers start to lift.

Ornamental colour against coastal duty

Set against Pandanus pedunculatus, this is the ornamental rather than the coastal native: narrower use, better leaf colour, the same requirement for space around it. Pedunculatus is the one for a dune front or a restoration planting; Red Edge is for a designed bed where the blue and red foliage is part of the palette. If the position gets brushed past, neither works, and the variegated Pandanus baptistii is the spineless alternative. Specify this one when the plant is a focal point with clearance around it and the foliage has to hold its own against render, stone or water. Larger container stock across the genus sits in mature trees.

Cutting off old foliage

Old leaves do not shed cleanly; they die and hang on the stem, so take them off flush twice a year with gloves, long sleeves and a sharp knife, then clear the trimmings rather than letting them collect in the crowns. Do not shorten leaf tips to tidy the plant, because the cut ends brown and stay that way. Feed at the start of the warm season and again in mid summer with a controlled release fertiliser spread over the root zone, plus trace elements on sand or fill, and keep mulch topped up but away from the stem bases. Rinse salt off the foliage occasionally on exposed coastal sites.

Choosing a size

This plant is available in 10 sizes, from 250mm up to 400L, priced from $59.95 to $3309.00 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. Every size here is established stock rather than a starter plant, so this line is intended for immediate effect rather than for growing on. Not sure which to choose? Read our guide to when to plant in Australia.