Weed control before planting
All weed growth should be removed before planting to reduce competition while new plants are
establishing. In particular all parts of creeping plants such as couch, kikuyu, bent and buffalo grasses and
bulbous plants such as oxalis should be carefully removed by hand or killed with a trans-located
weedicide (moves through all parts of the weed including roots) such as Zero. Chemical control should
be done prior to disturbing the soil so that broken off sections of weeds are not buried in the disturbed soil
where they might strike as new plants.
Weed control after planting
Weed control after planting is best achieved by non-chemical means, unless the problem is really
extensive, as you run the risk of damaging your natives. Heavy mulches, or weed mat laid down at the
time of planting and regularly maintained will greatly reduce the likelihood of weeds becoming
established. Maintaining plants in a healthy condition through good fertilising, watering, pruning, etc.
practices will allow them to out compete any weed growth. As weeds develop hand weeding, slashing,
mowing, etc. can be used.
PROPAGATION OF AUSTRALIAN PLANTS
Life of seeds
Some seed remains viable for years other seeds keep for very little time at all.
Banksia seed will keep longer if left in the cone (provided cones are treated to kill insects which might
cause damage). In the cone, Banksia seed lasts up to 6 years, out of the cone it lasts only 3 years.
Eucalypt seed keeps much longer if stored with the chaff. When cleaned, the lifespan decreases
Seed stored in glass or metal is better than that stored in plastic.
Plastic containers give off ethylene gas which is an inhibitor to germination.
Sexual versus - Asexual propagation methods
There are various reasons for choosing sexual propagation instead of asexual methods and vice versa.
Sexual propagation is often used for the following reasons:
When plants cannot readily be grown by asexual methods.
Production by seed is a lot cheaper, and often quicker than by asexual methods.
Seed of a particular plant may be plentiful, while cutting material is not.
Seed propagation is important in maintaining genetic diversity.
Seed propagation is used to breed new varieties.
Asexual propagation methods are often used for the following reasons:
To produce plants with the identical genetic characteristics as the parent plant (eg. flower colour,
variegation). Some plants do not produce viable seed, or their seed may be difficult to germinate, or
the seed may be unavailable at the time you are in the area collecting propagation material, or that
you need to produce that plant (you have orders from a customer) when seed is not available, or is
perhaps too costly.
Plants produced by asexual methods from a plant that has already flowered will usually flower
quicker than plants grown from seed.
Budding/grafting methods can be used to establish selected plants onto selected rootstocks (eg.
resistant to particular soil conditions or pests and diseases, or to create standard or weeping
It is absolutely vital that any source of seed for propagation is:
Totally reliable - you must know where it comes from, that the collector knows what they are doing.
From plants which are not likely to have hybridised.
Consider: Variation within a species
A form of Myoporum insulare native to the coast may tolerate a pH of 9
from the inland may only tolerate a pH of 7.5
There are red flowering forms of Eucalyptus ficifolia (also known as Corymbia ficifolia) growing in
south west Western Australia which produce flowers virtually every month of the year. The time of
flowering on the plants grown will vary according to where the seed came from.
Eucalyptus calophylla occurs in the wild on the W.A. coast from 1600km to 450 km south of the
Tropic of Capricorn. The plants which occur in the north would produce seed more adapted to
warmer climates, while seed collected in the south would grow plants more suited to cooler climates.
If you buy seed, do you know where it came from, and what sort of plants it is likely to produce?
Where can you get your seed from? This is very important in terms of:
Some seed suppliers do not supply pure seed (rubbish or weed seeds can be mixed with the seed).
Some seeds have not been harvested at the right time, hence % viability is lower.
Some seeds have not come from strong and healthy plants hence the vigour of the seed may be
The seed may have been stored poorly (eg. allowed to dry out), and hence the percentage of
viability is reduced.
The seed may be infested with diseases or pests (eg. insects eating seed).
b/ Gene pool
The place which a particular plant originated from gives it a range of characteristics which are very
specific to that plant (eg. Eucalyptus camaldulensis seed from one stand of trees might be very tolerant
of salt, while seed from another stand of Eucalyptus camaldulensis might not tolerate salt at all). Seed
sourced from local plants will enable you to produce plants that are adapted to local conditions (eg.
There are four main sources of seed:
1. Seed collected from the wild
Seed collected from plants growing in their natural habitat is less likely to be cross-pollinated, and you
can be more certain of where it came from and how it will grow than if you had purchased it. This can
be a cheap method of getting your seeds if you don't have to far to travel, and have the time to spare.
Many people get great satisfaction out of collecting their own seed. This may also be the only way to
get some particular species. Permission should be sought from landowners of privately owned
properties, or from the relevant state authority for public land. In Victoria this is the Dept. of Natural
Resources and Environment (Contact them)
2. Seed exchanges/Seed banks
Many Botanic gardens operate seed exchange programs, where they produce annual seed lists, and
swap seed with others who involve themselves with the program.
Such programs are particularly valuable as a source of more scarce varieties of plants. Some
associations and societies (eg. Society for Growing Australian Plants, Greening Australia, Landcare,
Community Environmental Groups and Nurseries) also participate in exchange programs, or maintain
seed banks for members and groups involved in re-vegetation programs. For example, the Victorian
Branch of Greening Australia hold the "Melbourne Indigenous Seed Bank".
3. Commercial seed suppliers
There are many hundreds of seed companies operating throughout the world. Some breed new
varieties of plants and grow seed crops to harvest. Others buy seed from collectors (who collect from
the wild or from gardens). Major problems of using this source include:
Collectors identifying seed source plants incorrectly.
Unreliable supply (if they can't supply, it's too late for you to collect for yourself).
Uncertainty about the quality.
Developing a dependence on the supplier.
Major advantages of using this source include:
Obtaining a seed source for plants which do not set seed well locally.
Savings on labour costs.
4. Collecting seed yourself locally
You or your representative might collect seed from plants on your property, or on other nearby
properties as it matures throughout the year.
They might also be collected from public parks and gardens or private gardens (with permission). The
major advantages of this source are:
You have a great deal of control over collection, storage and treatment.
You can be sure you have got exactly what you want.
You learn a lot more about the plants you are growing, because you see them in their mature state.
You can save on the cost of purchasing seed, though collecting can be time consuming, particularly
if you have to travel to collection sites.
Why do plants produce so much seed?
Much of the seed produced by plants gets eaten before it has a chance to germinate.
A lot of the seed produced will not end up in conditions suitable for germination.
Some of the seed will not germinate readily, even if it is in good conditions for germination due to
dormancy factors within the seed.
Some seed will form a "Seed Bank" that may survive for many years in the soil until conditions are
suitable for germination. A good example is the reappearance of species not seen in decades in areas
where the Rabbit Calicivirus Disease (RCD) has had a big impact on rabbit populations.
By providing suitable conditions we can generally get much higher rates of germination than would
naturally occur in the wild.
Collecting and harvesting seed – Guidelines
Always seek permission before collecting seed from private or public land.
Find a site: this may be as simple as keeping your eyes open or by seeking advice from local
forestry or conservation bodies or departments.
Take necessary equipment: plastic bags; writing equipment, labels, or small cards to write
collection details on. For larger scale collecting you might need handsaws, long handled loppers,
tarpaulins, a step ladder and more.
For tall plants you are best to obtain seed from commercial collectors. They generally use
equipment such as cherry pickers
, climbing equipment, or even high-powered rifles to shoot down
branches from high in trees.
Use gloves when harvesting. Many native plants have prickly or thorny foliage, some (eg.
Grevilleas) can cause skin allergies many will have resident populations of spiders, ants, etc. Use
common sense when choosing which clothes you are going to wear. Long trousers, long sleeved
shirts, and tough durable footwear are recommended. Safety helmets might be necessary if there is
a risk of heavy limbs falling.
While many seed pods can be readily picked off the parent plant without damaging the plant some
are a lot tougher to remove. Avoid pulling or ripping these off. Use sharp secateurs or similar hand
tools. This will reduce the likelihood of damage to the parent plants.
Always use sharp, and sterilised (pest and disease free) hand tools. A small container of a
disinfectant (eg. bleach, methylated spirits) can be carried to dip or wash tools in regularly.
Avoid harvesting seed pods when they are wet. This will reduce the likelihood of losses due to
Avoid damaging other plants. In your desire to get to a particular plant you could easily trample on,
or break branches off other plants. Be observant, take your time, and carefully pick where you
place your feet, and you will minimise the likelihood of causing damage to other plants.
Always label each batch of seed you collect, when you collect it. Information should include such
things as the species collected, the date collected, who collected it, where it was collected. This will
enable others who use the seed at a later date to be sure of what seed you have, how old it is,
where to go if you want more, and who to ask if you want more information.
Selecting plants to collect from
Collect your seeds from healthy, vigorous trees of desirable form, or having desirable
characteristics (eg. flower size and colour).
Where possible avoid collecting from isolated specimens, as self-pollination generally yields seed
of low vigour, and a limited gene pool.
To promote biodiversity take roughly equal amounts of seed from a variety of well spaced,
desirable plants. Ideally only harvest a little from each plant, particularly when there are lots of that
particular species available. As a rough guide no more than 10percent of available seed should be
taken from each plant. This will ensure that plenty of seed is left on the plant to maximise the
survival of the species locally, and helps ensure you have as wide a gene pool as possible in the
seed you have collected.
If you are quite sure that all of the plants you have collected from in a particular location are from
the same species then you can mix all of that seed together. If you are not sure then keep each
batch of seed separate (and separately labelled).
Knowing when to harvest seed is one of the most difficult tasks you will face when collecting seeds.
The time taken for seed to reach a harvestable stage from flowering will vary considerably from species
to species, and can range from a month or two up to several years.
Experience plays a very important role. Regular observation of plants you are interested in harvesting
from can often be critical, particularly for those plants whose seed ripens over a short period of time
and are not retained for long on the plant. Obtaining advice from others familiar with the plants you
wish to collect can be very worthwhile, as can research from relevant publications.
For many species the fruits are mature when they reach their full size and turn darker in colour and
become woody. Once mature many (eg. capsules, pods) will split open allowing their seed to be
dispersed. Some species will shed all of their seed within a few weeks of maturity (eg. Acacia). Some
species will retain their seed for a long time (eg. many Banksia, Hakea, some Eucalyptus.).
The seed of some plants will ripen over an extended period, while others will mature all around the
Fleshy fruits, common amongst rainforest species, will usually soften, and often change colour when
mature. These fruits are commonly eaten by birds and other animals, and the seed excreted from the
animals, and so dispersed away from the parent plant.
Methods of collecting
Natural seed fall
Large seeds or fruit can be collected from the ground. This method is most commonly used for
From low growing plants or branches
Readily detachable fruit or seeds can easily be handpicked. A tarpaulin or plastic sheet can be placed
under the plant and the plant is shaken, or branches are knocked with a stick to dislodge seed and/or
seeds. Some fruit might not be readily handpicked, but can be carefully pulled away from the parent
plant with a little effort, making sure to minimise any damage to the parent plant. Other fruit might need
to be cleanly cut away from the plant with a sharp knife or pair of secateurs.
From higher branches
Long handled saws, loppers or pruners can be used to remove selected branches. A rope saw can be
thrown over a branch, and the saw drawn backwards and forwards to cut the branch. Ladders can be
used (carefully), but they are cumbersome to carry around in the bush. A rope with a weighted end can
be swung around and thrown up into a tall plant to either wrap around a branch so that it can be
carefully pulled down within reach, or to dislodge fruit or seed so they fall to the ground. A rifle with a
telescopic sight is sometimes used to shoot through branches causing them to fall. This should only be
done by qualified (and licensed) people. Expert climbers with suitable equipment can climb tall trees
and cut down selected branches.
Ideally safety helmets should be worn when harvesting using any of these overhead methods to reduce
the likelihood of injury from falling objects such as branches or large, hard fruits.
If a tree has been cut down for harvesting then it may be possible to collect seeds from it. Trees should
not be cut down just to harvest seeds.
The mature fruits of many natives normally need to be dried before seed will be released. They can be
spread loosely on sheets of plastic or a tarpaulin. They should ideally be exposed to the sun, in a site
protected from wind, or placed in a well ventilated site under cover. Check regularly for pests (eg.
spiders, insects, birds, mice), and turn the fruits regularly. The outer pulp of fleshy fruit should be
removed prior to drying.
Drying may only take a few days in warm, dry weather, but may take weeks or even longer in cooler
Fruit of some rainforest species should not be dried.
Extracting the seed
Some seed is readily separated from the fruit (eg. Acacias, Hoveas, Hardenbergias), some is actually
dispelled as the fruit matures.
Seed held in hard woody fruits (eg. Hakeas, Eucalypts, Callistemons, Melaleucas, Leptospermums,
Kunzeas) generally open naturally over time, once removed from the parent plant. The fruits may need
to be banged to dislodge some of the seed.
Some seed however, might need a little help in being released. Many Banksias, for example, will retain
seed in their fruit (technically called multiple woody follicles - more commonly called "cobs") for many
years. The fruit generally require exposure to heat before they will open. This can be done in a variety
of ways including:
Throwing the Banksia cobs onto a BBQ for a short time (eg. a couple of minutes); this will burn off any
residual dried floral parts, and will often result in the follicles opening as the cob cools.
Putting the cobs in an oven at around 180 degrees C for about 15-20 minutes; remove them and allow
them to cool naturally, or dip them in cool water.
Once the follicles have opened, the seed can often be easily removed by banging the cob onto
something hard which will hopefully dislodge many of the seeds. There will often be two (winged)
seeds per follicle. Some seeds may need to be removed carefully using a pair of flat pronged tweezers.
Seeds with fleshy coverings should have the outer fleshy layer removed carefully using your fingers, or
a knife, and water. Alternatively the fruits can be pulped and seeds carefully strained off then dried.
Any chaff (infertile ovules in with the actual seed), leaf litter, old seed pod material, insects, spiders,
etc. should be carefully removed, making sure you don't damage the seed. For heavier seed such
debris can often be blown away carefully by blowing on them, or even with a hair drier held at a
suitable distance away. Some seeds can be separated from other material through a wire mesh sieve.
Seeds are alive and like any living thing they can be harmed by adverse conditions. Seeds of some
species do not store for very long at all...propagation should be done with fresh seed only. Most seeds
however will store for at least 6 months without loss of viability, provided the environmental conditions
of their storage are right.
Dusting seeds with an insecticide in powder form (eg. Carbaryl) can be effective in minimising damage
due to insect pests. Make sure when handling such pesticides, and seed treated with them, that you
use suitable rubber protective gloves. Also avoid breathing in any of the powder. Always wash exposed
skin after handling seeds treated in this manner.
The seed of many natives, particularly those from drier regions, and including many of the Eucalypts,
Acacias, Cassias, Melaleucas, Casaurinas, Callistemons, Kunzeas, Leptospermums, Hoveas, and
are ideally kept under low humidity and temperature conditions with little fluctuation in
these factors. The seeds are commonly stored in airtight, re-sealable glass, plastic or metal containers.
Alternatively snap-lock plastic bags can be used. Keep the containers in a cool, dark spot where they
are safe from vermin.
Seed from many of the fleshy fruited species has a short life span, and should be sown as soon as
At all times seed batches should be properly identified (ie. labelled).
Some types of seeds are much more difficult to germinate than others. In their natural state most
species have adopted mechanisms which allow germination to occur with relative ease. For many
"difficult to germinate seeds", it is possible to carry out some type of pre-germination treatment which
will increase the chances of success:
Seed of many native species will germinate readily if suitable conditions are supplied however the seed
of some species have built in dormancies that prevent them germinating immediately. This is an
adaptation that promotes survival. Such seeds will often germinate only after fire has passed through
the area, or after an extended period of time. To get such seeds to germinate they need to be treated
in some manner.
Typical treatments include:
Scarification is any process of breaking, scratching, mechanically altering or softening hard seed
coverings to make them more permeable to water. These treatments are commonly used on
species from the following genera: Acacia, Hovea, Hardenbergia, Pultenaea, Kennedya. Three
types of treatments are commonly used to scarify seeds. These are mechanical, chemical and hot
Mechanical Scarification involves such methods as rubbing them with sandpaper to thin the seed
covering, filing through the seed coat, nicking the seed covering with a sharp knife, cracking the
seed coat with a hammer or a vice. With each technique it is important to avoid damage to the
internal parts of the seed (and to yourself!). These techniques are used for larger seeds (easier to
handle), and where the amount of seed to be treated is small.
Acid Scarification is where dry seeds are placed in containers and covered with concentrated
sulphuric acid in the ratio of about one part seeds to two parts acid. Suitable acid resistant
containers should be used and great care taken in handling the acid (eg. chemical safety gloves
and face masks used). Time of treatment will vary from as little as ten minutes up to six hours
depending on the species.