Austromyrtus tenuifolia [Myrtaceae]; Narrow-leaf myrtle An extremely useful bushy shrub with a soft appearance.
Growing to 1.5m high, with fine needle-like foliage make it an attractive and versatile structural plant in various garden settings. Endemic to the Sydney Basin, where it is often found beside streams or in other damp places.
It is more commonly cultivated as ‘Copper Tops’, a hybrid between A. tenuifolia and midyim (A. dulcis, or midgenberry). Although this more compact cultivar is seen an desirable shrub in council park or street plantings, its unnaturally reddish new growth (given away by the name) makes it less appealing to us than the straight species. The natural forms do have red growth, however only on the new foliage during periods of growth.
As with many members of the Myrtaceae family, A. tenuifolia responds well to getting cut back. This could be tip pruning or hard pruning, and sometimes will even re-shoot from coppicing to 10cm high (although the latter is not guaranteed every time). From a design perspective, it can benefit from this, to develop a bushy growth habit. Our current practice is to tip prune upon planting, and then tip or hard prune every 6 to 12 months, depending on growth rate and desired mature size and density. With no pruning it tends to grow leggy or scraggly in appearance: particularly in poorer, heavier soils. This is not necessarily a bad thing; perhaps it could be desirable outcome in the right planting.
Having tried this plant in many garden situations it performs best in good light and well cultivated, organic rich soil that received reasonable watering in its first year. In shadier or drier locations, we find it be very slow growing. Lower foliage is occasionally prone to some thrips infestation in areas with poor air circulation, but this has never proved fatal or problematic for us.
