Articles and Fact Sheets

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Grevilleas for Sydney

Grevilleas

There are over 300 species and a huge number of bred or found varieties of grevillea in existence. The sheer number of them can make the beginner stuck for choice! Peter Olde (Grevillea Study Group Leader) suggests the following 10 species, 10 hybrids and 10 local species which are reliable and showy plants for gardeners to try in a Sydney climate garden. Note this list doesn't include the growing number of grafted Western Australian grevilleas which are also worth trying.

 

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Autumn Flowers for Sydney

autumn flowers for Sydney

Autumn has traditionally been seen as a lean time for flowers in the garden, however this needn't be the case. Listed below are some reliable plants for Sydney gardens which flower in autumn. In the bush, plants flower throughout the year. Help ensure your local fauna has something to feast on at all times! An asterisk (*) indicates plants native to the Sydney basin:

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School Gardens

who  are we ?
aims

When planning such a project, interest and enthusiasm are vital to its success. It should be seen as an ongoing program which is closely linked with many other aspects of the school's curricula. The coordinating teacher(s) need to be prepared to dedicate a considerable amount of time to the project for several years overseeing the area and educating and instructing students, other teachers and adults in the associated programs. Once the project is established it can become self-perpetuating. The following are some ideas which may help you to begin your project.

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Planning and Designing Australian gardens

Planning and Designing Australian Gardens – A few ideas to get you started.

Mounds/raised beds to provide improved drainage needed for good plant growth, create more interest in a flat garden and to screen out by raising plant height.

Create ponds/hollows for wildlife, to control water runoff, for water and bog plants and to allow rainwater to soak into the soil.

Using the space: Add seats to enjoy your garden. Make a sandpit and/or a cubbyhouse for children. Think of the wildlife by adding/making rocks, nesting boxes, above ground runways, access holes in fences. Add/install a compost bin for recycling green waste, a rainwater tank or two and a watering system to save water. Ensure open areas are covered with mulch or porous paving that allows rain to soak in. Make a solid edge to lawns that adjoin bushland to prevent lawn grasses invading the bush.

Use mulch: as it reduces evaporation from soil, helps to maintain constant soil temperature, keeps weeds to a minimum, reduces runoff and erosion, allows roots to better use the upper and richest layer of soil. There are two types of mulches: inorganic mulch which reduces humidity, increases light for plants requiring these conditions and organic mulch that naturally recycles leaves and twigs.

Keep what’s there: Retain any rocks and creeks and remaining bush plants. Trees - especially those that are framing any distant views you have. Dead trees providing they are not dangerous, as they are any ideal habitat for wildlife.

Bushland protection: If you live near bushland, avoid overhanging trees near house and planting flammable trees and shrubs near your house. Avoid plants with high oil content as they burn easily. Clean up dead growth and shrubby plants near your house. Use hard surfaces or inorganic mulch near and around your house.

Choosing plants: Plants provide cool shade, protect plants and houses from heat and cold, make our suburbs beautiful, provide oxygen, reduce glare, makes windbreaks, filter dust and pollutants from air and screen undesirable views, to name a few.

Choose plants with a purpose: Reduce fertiliser use by choosing plants whose roots are adapted to poor soils. Good examples are species of Banksia, Grevillea, Acacia, Baeckea, Bossiaea, Brachysema, Chorizema, Hypocalymma, Jacksonia, Lechenaultia, Pultenaea to name a few. Or add fertiliser (nitrogen) to soil naturally by choosing Acacia, Cassia, Casuarina, Pea flowers and other Australian legumes.

Save Water: Plants will need frequent watering for a few months after planting until they are established so best to plant new plants, in late winter/early spring or in autumn. Give established plants a deep soaking occasionally or not at all when very dry (the plant will give you visual clues if it needs water). Water plants in the evening to avoid loss by evaporation. Try to group plants together according to their water needs. Use an efficient watering system/soaker hoses rather than a hand held hose.

Encourage nature's exterminators by protect snail-eating Blue Tongue Lizards by not using chemical snail bait and providing logs, rock piles and other cover for retreat. Encourage insect-eating birds, frogs, spiders, lizards, bats and marsupials. Avoiding use of insecticides as that will protect ladybirds, lacewings, hover-flies, bugs, praying mantis and wasps which prey on insect pests; protect butterflies, dragonflies and bees.

Jeff Howes

© 05/09/2012

Adapted from a draft, Australian Plans Society NSW fact sheet titled ‘Planning suburban gardens for all of us’ dated Jan 2003.

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Soils and Plant selection

 

Soils ain’t soils and plant selection

I have been gardening on heavy northern Sydney soil for many years and have had my fair share of plant losses. My main problem was due to the fact that I planted plants that naturally grow in light soils and hence have a week root system that is unable to penetrate my heavier soils. When there is adequate rainfall and soil moisture this is not too much of a problem. However, when the soil dries out, these plants are the first to die as they do not have a root system extensive enough to get enough moisture.

In the past, when selecting plants, I often did not worry too much about what soil type they grew in as I was more concerned with height, attractiveness of the flowers, light requirements and leave texture etc. I now take into account the plants natural habitat and soil type that it grows in after reading a few years ago, two excellent Australian Plant Society books both written by Ken Newbey. The first was West Australian Plants for Horticulture -1 (published in 1968) and the second was West Australian Plants for Horticulture -2 (published in1972). In Ken’s second book on page 135 under the heading of conclusions all become clearer as to why I was having plant losses. While the book is written around Western Australia, the comments he makes about soil types, climate and selection of species applies to all, well most I suspect of Australia. Some, but not all of the points he made are (and I quote):

  • Species which occur naturally in shallow soils should do well in deep soils of the same type but the reverse is not the case. Species occurring in shallow soil have very strong root systems necessary to penetrate the hard clay subsoils. Species growing in deep soils do not have this strong root system and have extreme difficulty in penetrating the hard clay subsoil. Species growing in deep soils have a much more even moisture content throughout the year with only very temporary waterlogging whereas the shallow soil species have a wider range of moisture content in the top soil and more chance or waterlogging.
  • Using the five topsoil types as a standard – sand, sandy loam, loam, clay loam and clay - plant species are usually adaptable enough to do well in one soil type either way. There is a possibility that the species may be suitable two types either way e.g. a species which occurs on loam should do well on sandy loam and clay loam and may be successful on sand and clay. A large number of our species are selective in their soil type and this guide should be followed carefully.
  • Species which occur naturally in waterlogged areas usually do well in drier situations but the reverse is not the case. This means that species which occur naturally in dry situations should be planted where they will not get excess water.
  • Rocky soils are often essential for growing species in exposed places so that they form a stable root system and not suffer from root movement which is either retarding or fatal to the plant. Rocks also assist drainage.
  • Within reason, the rainfall is not of a great importance. What moisture is retained in the soil is the main factor. For instance, rocky ridges in the heavy rainfall areas may have lower annual moisture content than areas surrounding massive rocks in semi arid areas where there is excessive run off.

The more I garden the more I realise that there is more to selecting plants than just using the criteria that they are ‘local’ or look nice. I suspect that we have a lot to learn about reduced rainfall and the effect of climate change on how we garden. We may need to be lot more clever in plant selection than we have been in the past to help minimise plant losses.

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Rejuvenating an old garden

Rejuvenating an old garden

(copied off the APS web site – see below)


What are the problems with your native garden?

We always overplant!

I don't think I have ever met a native plant grower who did not believe that they could fit one more plant into that small space in the garden, even though they know it will grow 2m by 2m. We are ever optimists! This generally results within a few years in a garden that is overgrown, with pathways buried and the characteristics of individual plants lost. If we also unwisely chose plants that turned into large trees, we may well also be faced with the considerable expense of removing them.

We sometimes choose the wrong plants.