Propagation of many of our native plants from seed can be very rewarding and a great method of growing a large quantity of plants at little expense.
If you have not had a great amount of experience in growing plants from seed I suggest you start with some of our more common and easy to propagate plants. You can collect seed from different species of plants throughout the year but the majority of our native plants produce seed which ripens over the summer and autumn months. Most seed does not store well and will lose its viability very quickly. The general rule I use is fresh is best, collect, clean and sow.
Large wet seeded plants like Karaka, Taraire, Puriri etc need to have the outer layer of flesh removed before they are dried and sown. Dry seeded plants Pohutukawa, Manuka, Flax etc need to be separated from their husks (the kitchen sieve can be useful). If you have to store any seed make sure it is clean and dry then place in a plastic bag in the fridge labeled with name and date.
You can sow seed directly into the ground but for best results I would recommend using a container (polystyrene mushroom boxes are ideal). The container must have sufficient drainage to ensure it does not become water logged. I always use a commercial seed raising mix. Seeds should be sown thinly and covered lightly with the same mix. Place the container in a warm, sheltered place with light but not in full sun and with protection from heavy rain. Keep the mix moist but not water logged. Never let it dry out. Good ventilation is important, like us they need oxygen to grow. Regularly check your seed trays for any bugs or disease.
There is an abundance of worthwhile information written about propagation and there are also several books on growing NZ Native plants.
However, even when it becomes more complicated the basic conditions still must apply, e.g. viable seed, good growing media, correct watering, a suitable situation for germination and good hygiene. Even after reading all the information on propagation you like which is a really good idea, you cannot beat the learning which comes from practical experiences or mistakes of sowing your own seeds.
All growers I have met develop their own techniques and methods to achieve successful germination. Mistakes can be rewarding.
Remember it's green eyes that grow good plants from seed not green thumbs!Guy Bowden
Every year we collect and grow our local Astelia banksii, a silvery flax-like plant which grows on coastal cliffs. I once waited eighteen months and with no sign of germination I eventually gave up, stacked these trays on top of each other outside ready for disposal. A few weeks later I lifted the top tray which was exposed to full sun only to discover that the tray underneath had perfect germination of 500 plus seedlings and so had the next tray below and so on all the way to the last tray on the bottom of the stack. So we now always cover our Astelia trays to keep them in the dark and within a month we have Astelia banksii seedlings.The knowledge will come from experience and as with any subject there is always more to be learned.
Remember it's green eyes that grow good plants from seed not green thumbs!