Sunday, April 21, 2013

Planting a Native Australian Shade Garden in Sydney

Bird's Nest Ferns
I'm visiting my daughter, Liz, in Sydney, Australia, where she's rejuvenating the landscaping around her home. Like most gardens in this country, hers is dominated by non-native plants -- in this case English cottage garden plants such as camellias, azaleas, lilies, iris, and daffodils.

This would be fine, except that imported plants have an unfortunate tendency to "escape" from gardens and displace native species in the wild, causing irreparable harm to the delicate ecosystem here. Australia's geographic isolation has allowed its native plants and animals to evolve uniquely, and many species aren't found anywhere else the world. Since European settlement, 61 native plant species have become extinct, and a further 1,239 are threatened. Although many factors contribute to this tragic loss of diversity, the introduction of invasive, non-native plants into the ecosystem is a major one.

With this in mind, Liz has accepted the challenge to replace non-natives in her garden with native plants indigenous to the Sydney area. And a challenge it is. The small part I've taken has made me appreciate why people prefer gardening with familiar plants from their own countries (and may explain why Australia has so many non-natives). There is so much to learn! Australian native plants aren't like anything I've dealt with before. Their appearance is unfamiliar. I don't know their growth habits or their sun/shade/water/nutrient/soil requirements. I can't distinguish a weed from a desirable plant, or a native from a non-native

To meet the challenge, Liz has adopted a phased strategy, planning to take on just one section of the landscaping at a time, clearing it and figuring out which plants will work best in that particular spot. This should make the learning curve a bit less steep. Fortunately, most of the non-native plants in her yard are fairly well behaved and not known to be "escapees," and the problem plants can be controlled by removing their flowers and seed pods until such time as the plants themselves can be removed.

During my visit, I've assisted with Phase I: rehabilitating the garden across the driveway from the patio -- the most visible one. The whole garden is shaded all winter, and the front of it's sunny in summer.

Phase I: This garden hosts several invasive species, including Fishbone ferns, which are native to another part of Australia, but invasive here, where they choke out other plants.  The fence in back is covered with Chinese wisteria that Liz will remove in the  future and replace with native Kangaroo vine. Just as we experience in Seattle, the wisteria wants to take over the world, and will climb trees and strangle them if not constantly cut back. 
Liz clears the ground, digging out roots and tubers. Fishbone ferns seen on the far left of this photo are in a Phase II section of the garden and will be removed later.
We acquired these natives in an expedition to two native plant nurseries. Liz selected plants with a mixture of growth habits, adult heights, and foliage. Small plants are less expensive and easier to plant than larger ones. See below for her plant list.
Here's a close-up of several ferns, which should do well in this shade garden.
The planting begins.

Everything's now in the ground, including some stones for a path to the birdbath. As the plants mature, they will overtake the empty spaces and create a full, lush effect.
Here's a different viewpoint. Liz has started to apply a thick layer of mulch to retain moisture and help give the plants a good start.
And here's the next section waiting for rehabilitation.
Liz's list of shade-loving (or tolerant) Australian native plants and their habitat value:

Indigofera australis - native indigo, shrub, 1.5 m tall.  Produces small pink flowers which attract native bees and butterfly larvae, seeds attract birds.
Dianella caerulea – flax lily/paroo lily, perennial herb, 1 m tall. Purple berries attract birds and butterflies.
Alpinia caerulea - native ginger (and Atherton ginger*), perennial herb, 1.5-3 m tall. White flowers and blue fruit attract birds.
Lomandra fluviatilis - no common name, NSW ENDEMIC, 50 cm tall, tufted perennial herb. Attracts seed-eating birds and provides shelter for small birds and lizards.
Cissus antarctica - kangaroo vine/water vine, climbing vine. Provides nesting sites for birds. Purple fruit attracts birds, moths and ringtail possums.
Macrozamia communis - burrawang cycad, NSW ENDEMIC, 3 m wide, 1-2 m tall. Large seeds attract marsupials, large birds and fruit bats. However, they are extremely toxic to humans and non-native animals/livestock and can cause death.
Cordyline stricta – slender palm lily/narrow leaved palm lily, shrub, 2-3 m tall.  Attracts butterfly larvae.
Blechnum patersonii - strap water fern. Provides shelter to small birds and lizards.
Microsorum diversifolia - kangaroo fern. Provides shelter to small birds and lizards.
Doodia aspera - rasp fern. Provides shelter to small birds and lizards.
Asplenum australasicum - birds nest fern. 
Adiantum spp. – maidenhair fern (already in the garden).
And then of course the sun-loving Banksia integrifolia – coast banksia, tree, 25 m, to create more shade for the shade-loving plants.  Large flowers attract nectar-feeding birds and seeds attract small mammals.

*The Atherton ginger was the only plant we brought home that is not indigenous to the Sydney area. This ginger comes from Queensland, but we fell in love with the red underside of the leaves.

For an update on Liz's progress, see A Native Shade Garden in Sydney -- Year Two.

For more information on Australia's native plants, see: 

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