Propagate by semi-ripe cuttings taken in summer, or by seed. Requires moisture-retentive, but well-drained soil with neutral to acid pH, and partial shade. It grows very slowly and may take 15 years from planting to produce fruit. Once it begins fruiting, however, it is usually possible to harvest from the tree 3 times a year, and fruiting may continue for over 100 years.

And on cardamom:
Propagate by dividing the rhizomes, or sow seeds. Rich, slightly acidic soil with excellent drainage. Needs frequent watering. Grow in shade, or partial shade, protected from wind. In temperate climates it is unlikely to produce flowers or fruit. Needs protection from frost. In cold climates, it is best grown indoors, where it should have no direct sun, only diffused house light.

Sorry, not very helpful, but I think both are worth a try.

Black cardamom is a different genus and species; Amomum subulatum.

They are both zingiberaceae (ginger family). I've never seen Black cardamom growing, but I have a green cardamom plant in my garden. Apparently it's not suficiently hot or tropical in Adelaide for them to set fruit, but they grow as an interesting talking point in the garden. I don't think the seed from Cardamom bought as a spice would be viable, though I'm not sure... you could try it!

Star Anise is a very interesting plant. It's a beautiful tree from South China and Vietnam, no longer known in the wild, only in cultivation. It's a tropical tree of the family Illiciaceae. This is a very ancient group of plants most closely related to Magnolias (same sub-class). I have serious doubt that you could get the seed to germinate, or the tree to grow here for that matter. If I was going to try I would scratch the hard seed coat and steep the seed in boiling water before planting in sterile seed raising mix, then cover the pot with plastic to maintain a warm humid environment. If it germinates PANIC! You'll need a glasshouse to keep it happy.

There are some other members of the family, ie. Illicium floridanum which grow in cooler climates, they are however toxic.

try All Rare Herbs - Mapleton Qld. You have to call him and ask for a catalogue on:- (07) 5446 9243.

As for the cardamom, I'd LOVE to get it growing from seed. I should take some seed to work and process them there (Plant science laboratory). They are tricky little buggers.

Regarding the vanilla, what they will sell you will be a cutting, not seed, so you get a head start! Grown as an indoor plant on a sunny windowsill would be a good place to try.

The star anise seeds apparently what are called 'recalcitrant', which means that will likely never germinate if allowed to dry out significantly. See here:

http://www.dfsc.dk/pdf/Seedleaflets/Illicium verum_52_int.pdf

I have tried several times unsuccessfully to get the seeds from pods I bought in bulk at the market to grow.

You'll need to find someone selling plants or fresh pods, not dried.

Good luck.

Is it possible to send me some plants of true star anise from Vietnam ?
I'd like to cultivate it.
Thanks
jan