I have had a recent project preparing Tagasaste Cytisus proliferus seeds for growing. As they are designed for tough conditions being native to the Canary Islands, much like our Australian native plants, the seeds are quite robust and require some treatment before planting out. The seeds protective coating will degrade over time as it is exposed to water and weather and soil organisms – and this allows water to penetrate the outer coating of the seed and start the germ to growing.
To fast track this process I have been covering the seeds with boiling water. I have a number of seeds in a ceramic ramekin and I tip boiling water over them from the kettle whenever I make tea. Once cool I strain off most of the water and used hot water again. After about the second or third time I start to notice some seeds turning from black to brown and swelling – almost double in size.
I remove these seeds and put them into another dish with a little water to keep moist. I keep repeating this process of straining off cold water and adding boiling water. Removing the swollen seeds and repeating again. Each time more and more of the seeds present themselves as ready for the next stage.
I then place them in a container of potting mix. Presently we are experiencing scattered showers so I have the pots out where they can get some of the wonderful rainwater to really trigger the growing process.
Tagasaste is planned as one of the main fodder crops for our garden as I can hopefully get enough to grow from seed and they grow well in the sandy soil – thus making them a great pioneer tree, much like the wattles.
The following information from Greenharvest is handy.
Recommended Planting Time: Spring, or during the wet season, soil temperature should be at least 20°C for germination, a higher soil temperature will give a more even germination.
Planting Depth: It can be direct-seeded, or planted into forestry tubes and later transplanted. Sow the seed 2.5 cm deep.
Details: Soaking seeds overnight will improve germination. Protect young plants from all grazing animals.
Inoculant: A group of bacteria called Rhizobium live in a symbiotic relationship with many legumes. This is a big advantage to the plant, as it is able, once inoculated, to produce its own nitrogen, from the soil air. The bacteria are stored in peat, and as this is a living culture, it must be treated with care. It should be stored in the fridge and used within 3 months. Do not separate from the seed packet as the inoculant attached is specific to the individual legume. To use, moisten the seed with a small amount of milk or water and stir in the inoculant until seeds are coated. Do not inoculate the seed until you are ready to sow it and do not leave the inoculated seed in the sun.
Update : 12th October 2017 – 21 days or so after the initial planting we have a small forest of tagasaste seedlings emerging and thriving. I’ve managed to keep them safe thus far after the initial digging up of seedlings from the first pot by some unknown, hungry critter. For some reason it is a thrill to me to see these seedlings. It is like a sign of hope for the beginnings of the forest that is yet to come. Simple. Natural. But deeply satisfying.
In order to give them a fighting chance from slugs, snails and such things I have sprinkled them with diatomaceous earth.