Native Seed Germination

Sunday, 06 July 2008 05:14 | Written by MCCG Editor |

Germinating Seed of Local Rainforest Plants

There is increasing interest in our area in propagating seed of local trees, either for growing on our own properties, or for exchange with others with similar interests. When collecting seed for propagation, there are several factors to bear in mind – it should be fully ripe and not insect-damaged, it should be collected from several plants and not just one (to avoid inbreeding effects) and it should be correctly identified (collect and press a specimen with leaves and fruit between sheets of newspaper; if you don’t know somebody who can identify it for you, give the specimen to Bryan Hacker (phone 3374 1468), and he will arrange for identification. Of course, it is also important that you receive permission from the landowner to collect seed on his/her land.

Different species have different requirements for seed treatment, if they are to germinate satisfactorily, and even with optimal treatments, seed of some species takes several months or even longer to germinate. The Department of Natural Resources (1998) has put together a list of recommended seed treatments for a range of species together with germination periods and the accompanying table lists those native to our area. Seed treatments included in the article are:

A – sow seed directly
B – pour cold water over seeds in a container and soak for 24 hours
C – pour cold water over seeds in a container and soak for 48 hours
D – pour just-boiled water over seeds in a container and soak for 24 hours
E – pour just-boiled water over seeds in a container and soak for 48 hours

Having treated the seed, if recommended, it should be scattered, not too densely, on a bed of a free-draining potting mix in a polystyrene box or other free-draining container (where you only have a few seeds, a flower pot could be used, or seeds could be sown individually in small pots). The potting medium should be free of weed seeds. The seed should then be covered with a layer of the potting mix; where the seed is small, it should not be buried too deeply (no more than about five times the diameter of the seed). After sowing, the seeds should be kept continuously moist (but not water-logged). It is sometimes desirable to cover the box with wire mesh or netting to keep out rats or cane toads.

Seed Treatment and Germination Periods

Species	Common name	Treatment	Germination period
Acacia spp.	Wattles	D	5-10 days
Acmena smithii	Lillipilli satinash	C (fresh)	4-6 weeks
Allocasuarina spp.	She-oaks	A	2-3 weeks
Araucaria cunninghamii	Hoop pine	A	6-12 weeks
Argyrodendron trifoliolatum	White booyong	A (fresh)	3-4 weeks
Brachychiton discolor	Lacebark	D	1-3 weeks
Callistemon spp.	Bottlebrushes	A	1-3 weeks
Castanospermum australe	Black bean	A	3-12 weeks
Casuarina spp.	She-oaks	A	2-3 weeks
Commersonia bartramia	Brown kurrajong	D	2-6 weeks
Cordyline spp.	Cordylines	B	1-3 weeks
Diploglottis autralis	Native tamarind	A (fresh)	2-4 weeks
Dysoxylum spp.	Mahoganies/Rosewoods	A (fresh)	2-6 weeks
Eucalyptus spp.	Eucalypts	A	1-3 weeks
Ficus spp.	Figs	A	2-6 weeks
Gmelina leichhardtii	White beech	A	12-24 months
Harpullia pendula	Tulipwood	A	2-6 weeks
Hymenosporum flavum	Native frangipani	A	4-12 weeks
Lophostemon spp.	Brush and Swamp box	A	1-2 weeks
Mallotus spp.	Kamalas	A	2-6 weeks
Melia azedarach	White cedar	A	2-4 months
Pandorea jasminoides	Wonga vine	A	1-3 weeks
Pittosporum spp.	Pittosporum	E	2-6 months
Podocarpus elatus	Brown pine	C	1-3 months
Rhodosphaera rhodanthema	Deep yellowwood	C	2-3 months
Stenocarpus sinuatus	Wheel of fire	A	4-6 weeks
Syzygium spp.	Lillypillys	C	2-6 weeks
Toona ciliata	Red cedar	A	2-6 weeks

As shown in the table, it can be weeks or even months before the seedlings of some species can be expected to appear. When they are 5-10 cm tall, they can be carefully teased apart and individually planted in 5 cm tubes or small flower pots, to be grown to 30-50 cm height before planting out in the field.