‘Frog Hollows’ in the garden
Frogs are an important part of the ecosystem and yet their numbers are dwindling. They are carnivorous animals, eating a large variety of insects, spiders, small reptiles and fish. Different species live in different habitats – in trees, among grasses and in rock crevices. Thus, many species can live in a small area. What they all need, however, is water for breeding. Their eggs, laid in water, hatch into aquatic, herbivorous tadpoles that gradually change over 1 – 12 weeks into frogs.
The sloping terrain of many Brisbane gardens provide an opportunity to increase frog numbers. Hollowing out an existing low-lying part of the garden that normally collects rainwater, lining it with a waterproofing substance like clay covered with soil, is the start of your own ‘Frog Hollow’. The planting around this area is as important as providing a water-filled breeding place for the frogs.
Thick edge planting of several types of medium height sedges and grasses discourage cane toads from the rain garden. Tall sedge (Carex appressa) is a hardy plant that survives well in both wet and dry conditions. Its lime-green upright foliage contrasts well with common tussock grass (Poa labillardierei) with blue-green leaves. Another clumping species, the creek matrush (Lomandra hystrix), with its strap-like leaves grow naturally along creek banks and are renowned for erosion control.
Two plants that like root immersion in water are the woolly frogmouth (Philydrum lanuginosum) and the triangular mat club rush (Schoenoplectus mucronatus). The lovely yellow flower of the woolly frogmouth resembles the open mouth of the frog. It forms clumps along the margins of waterways and boggy areas. Its lime-green leaves develop reddish tones as they age. The triangular club rush has triangular leaves and forms attractive clusters of seed heads on its rigid stalk. Both assist in oxygenating the water for the tadpoles and provide an exit point for the newly metamorphosed frogs.
The Native Elderberry
The native elderberry (Sambucus autralasica) is a useful bush food to have in the garden with its culinary uses akin to exotic elderberries (used to make elderberry wine, cordials and jam). Since it is a shrub that only grows to 4m and can be readily pruned to keep it at a suitable size, this plant will not take up a lot of space.
The plant is found in the wild along the edges of rainforests from north Queensland, along the east coast to Tasmania. In cultivation, it tolerates a wide range of conditions from sandy to clay soils, and light to heavy shade. It prefers a moist, well mulched soil that is neutral to slightly alkaline but will grow in exposed, windy areas so long as there is no salt spray. It can also survive in areas with atmospheric pollution. It has shown no indication of weed potential.
With its glossy green compound leaves composed of 3 – 5 lanceolate leaflets, and terminal clusters of tiny cream-yellow flowers during spring and summer, this makes an attractive addition to even the smallest garden. The round, yellow fruit forms from February through to July. Although each individual fruit is small (about 5mm in diameter), they are easily picked since they occur in dense groups. That the fruit can be eaten raw (the taste varies from slightly sweet to slightly bitter) or cooked and attracts fruit-eating birds is an added advantage to growing this plant.