Gardenia augusta Radicans (Gardenia jasminoides)

Radicans is the ground hugging form, a low spreading plant with fine small leaves that runs sideways rather than up and stays well below knee height. What sets it apart is scent at ground level: small double white flowers, as heavily perfumed as any gardenia, carried on a plant you look down on rather than into. It is used as a fragrant edge along a path, as mass planting beneath a window, and spilling over the rim of a wide pot or the face of a low retaining wall.

Cold wet winter soil under a ground hugging gardenia

Part shade suits it, with morning sun and shelter from hot afternoon glare, and it wants the same acidic, compost rich, free draining ground the taller gardenias need. Space plants around 40 to 50cm apart for mass planting so they knit into continuous cover, and mulch between them until they do. Keep water even through summer, since a shallow rooted spreader dries out faster than an upright shrub in the same bed.

Late winter yellowing is the complaint that comes back every year, and Radicans gets it worse than its upright relatives for a structural reason. Its roots sit in the top few centimetres of soil, exactly the layer that stays coldest and wettest through winter, and iron uptake all but stops in cold wet ground even where the pH is right. On alkaline soil the two problems compound and the whole planting goes pale at once. Fix drainage before anything else, ease off watering over winter, and feed with chelated iron and an acidic fertiliser once the soil warms in spring rather than in the middle of the yellow spell.

Radicans or Florida: two different jobs

Buyers weighing Radicans against Florida are choosing between two different jobs. Florida builds a rounded shrub you can clip into a low hedge with a face; Radicans hedges only in the sense that a mass planting knits into a continuous ankle high edge, and pushing it upright leaves a bare, patchy mat. Magnifica is larger again in leaf and flower and belongs in a deep border. Pick Radicans for the front edge of a bed, for underplanting beneath taller shrubs, for a wide shallow pot, or anywhere a taller gardenia would block a view you want kept open. Grandiflora Star, the single flowered form in this hub, stands upright again and belongs in a pot or a bed corner. The rest of the group is in gardenias.

Shearing a gardenia mat and feeding it

Trim after the main flowering flush with shears, taking the tips back lightly to thicken the mat and cutting out any long shoots that lift above the rest. Do not cut into old bare wood at the centre, which reshoots slowly and leaves a hole in the meantime. Feed in early spring with an acid loving plant food spread across the whole planting rather than dropped at individual stems, since the roots run well beyond each crown, and follow with a lighter second feed in midsummer. Watch older leaves for scale and the sooty mould that trails it.

Choosing a size

This plant is available in 4 sizes, from 140mm up to 300mm, priced from $16.95 to $88.95 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. These are younger plants, priced for planting in quantity, and they establish quickly once in the ground. Not sure which to choose? Read our guide to when to plant in Australia.