The importance of local provenance
The use of locally indigenous plants in revegetation projects is a vital key to the success and integrity of these projects. Whilst the complexities of this strategy have been widely researched and documented, in short, the use of local native species ensures two main important factors:
- The resultant plants of locally collected indigenous seed will be the best suited to the climate and other environmental conditions of your site, allowing them to contribute positively to the ecology of your local area
- The genetic diversity of our native vegetation will be preserved and maintained, preventing the spread of 'hybrids' which can ultimately weaken the gene pool over time, making our vegetation less robust and resilient.
Permits and permission
There are no permits or permissions required for collecting seeds from your own property. However, collecting plant material from anywhere else requires the written permission of the relevant landholder or management authority. In South Australia, a permit is required to collect from public lands including Council Reserves, National Parks and roadsides. Applications are available from the Department for Environment and Heritage website (www.environment.sa.gov.au). Permits are issued for a 12-month period.
 |
|
Seed collecting for large commercial
operations. This volume is beyond the
scale of most local projects.
Photo courtesy of Neville Bonney,
from the book What Seed is That?
|
Seed banking
At the planning stage of your seed collection it is important determine which species are required for your revegetation project and of those species, which ones can be locally sourced and collected. Assistance in this planning stage can be sought from Catchment Care officers, Bush Management Advisers and local Landcare groups.
You will also need to determine the times of year when seed will be available from target species. This can vary considerably between species. A fantastic resource for any seed collector in South Australia is What Seed Is That? by Neville Bonney (available from Greening Australia, and good environmental bookstores). This book includes information on timing and methods of seed collection, as well as descriptions, illustrations and propagation hints for hundreds of South Australian plants.
Two main types of fruit
As a general rule, plants which produce woody fruits such as eucalypts, melaleucas, tea-trees, sheoaks, hakeas, and banksias, may retain their ripe fruit all year round, increasing the window of opportunity for collecting seed. Seed is ripe when the fruits turn from a greenish colour, to a brown-grey colour. It is important to check that the valves on the fruit are still closed. Seed ripeness can also be checked by cutting open the fruits to observe the colour of the seed. Unripe seed is moist, green and pulpy, whilst ripe seed is drier and darker in colour, usually red, brown or black.
Plants which produce seed in pods (such as the acacias, pultenaeas, and other pea-flowered plants) need to be collected as soon as they ripen and before they drop off the plant between mid and late summer. Seed is ripe when the pods change from green to brown or black, dry off and begin to split open. Seed ripeness can again be checked by cutting open the fruit.
Collection methods
Whilst commercial collectors might employ the use of chainsaws and large tarpaulins for the purpose of collecting fruit, smaller scale operations will be effective using buckets or paper bags to gather fruit by hand. It is important to remove as little plant material, and to do as little damage to the plant as possible while collecting fruit. Pruning secateurs with extendable handles may be useful for cutting fruit from higher branches.
 |
|
Smaller-scale operations will be effective using buckets or
paper bags to gather fruit by hand.
|
How much seed should I collect?
In most cases, once seed is ripe, a useful amount of seed can be collected in a short time. It is important that ample supplies are left for local species which may utilise seed and fruits as a food source. National seed collecting guidelines (FloraBank - visit http://www.florabank.org.au/default.asp?V_DOC_ID=755), recommend that no more than 20% of seed produced by any individual plant be removed. These guidelines also suggest collecting from five widely spaced individuals plants of the same species, so that seed is not just collected from closely related specimens.
Drying, gathering and storing
Woody fruits need to be dried in order to open up and release seed. Pod fruits will also release seed more easily once thoroughly dried. Start drying immediately after collection to prevent fruit and seed from going mouldy. Fruit can be placed in paper bags and open trays and left at room temperature (15-30oC) in any area with good circulation. Smaller fruits, like eucalypts will dry out completely in a few weeks, while larger woody fruit, like banksia or sheoak fruit, may take several months.
Shaking or threshing dried fruit will usually suffice for extracting the seed. Seed can then be shaken through a kitchen colander for those species with fine seeds and woody fruit, whilst a larger mesh size, like a compost sieve, is useful for separating pods from seed. This process will help to remove the last of the non-seed plant material.
Once clean seed has been obtained, it should be stored in an airtight container (such as a zip-lock bag or jar) in a dark, cool, dry environment. Most seed, if cleaned and stored properly, will remain viable for many years. In some cases, insects can persist on seed throughout the collection and extraction process, and collectors may choose to protect their seed from insect attack by adding a small amount of insecticide compounds like magnesite or naphthalene.
Top