Fact Sheet: Seedling Production
Presenter: Jerry Coleby-Williams, 12/11/2011
SERIES 22 Episode 40
JERRY COLEBY-WILLIAMS: I love to grow plants from seed. It gives me great joy to create new life. And that's why I'm here in Gatton, in outer-western Brisbane, at this huge nursery, to see what we can learn from how they propagate and grow their own seedlings.
CHRIS JOHNSON: The main rules for germinating the seed is controlling the environment which includes the light, the moisture and the temperature. What we try and do here is control those factors as much as we can.
JERRY COLEBY-WILLIAMS: Chris Johnson is the nursery manager here and every year, he oversees the growth of about 50 million seedlings including annual and perennial flowering plants and a wide range of vegetables.
CHRIS JOHNSON: Automation plays a massive part in the sowing of all our seeds. We control the seeding by an automated seeding machine which goes into an open mix made up of coir, peat moss and Thermiculite.
JERRY COLEBY-WILLIAMS: There are 2 seed sowing machines. The drum machine does mass planting of easy to handle ground-seed types and this needle machine individually sows irregular and awkwardly shaped seeds.
CHRIS JOHNSON: The next process after the seed has been sown is to bring them in to the germination chamber. What the germination chamber provides is optimum environment for seed germination. Each variety has a different optimum temperature and humidity to strike germination, so we try and do is provide that in these chambers. We run a 23 degree chamber and a 17 degree chamber, depending on what the variety requires. It can be anywhere from 2 to 10 days for full germination.
So you can see here, that's something that's just been sown. That'll stay in here until we see the first root starting to come out of the seed coat and that's the optimum time to remove this seed for the next stage of germination.
JERRY COLEBY-WILLIAMS: Once the seeds have germinated, they're moved into the weaning house.
CHRIS JOHNSON: So this is the next stage of development after the seed has germinated and the radical has emerged from the germination chambers. The whole idea of this house is to provide a moderate environment with both heating and cooling and to allow a lot more light to come into the house so we adjust that through a retractable shade. The whole idea, basically, is to get full cotyledon emergence, so the first true leaf emergence and then we can release them out into the big wide world.
JERRY COLEBY-WILLIAMS: When it comes to feeding, the seedlings don't need much. There is a slow release fertiliser in the growing mix and that is topped up as required by foliar feeding via irrigation.
What percentage of vegetables do you propagate as compared to flowers?
CHRIS JOHNSON: Well we're actually finding that's changing a lot now. We used to grow about 40 percent vegetables, now that's actually taking over and it's about 60 percent of our range. What we're finding, the trend is starting to come towards more the colourful type varieties such as you can see with your red spinach and your red type lettuces and the old favourites are still coming back like your heirloom tomatoes and that type of thing. So the diversity is ever increasing.
JERRY COLEBY-WILLIAMS: Once people have got their seedlings, what advice would you give them for planting?
CHRIS JOHNSON: The best advice we can give on planting of vegetables is, before you go in and choose your seedlings, know your garden, know the settings, know where your shade is, know where your lighting is. Always refer to the label with the spacings and that type of thing. Make sure you get accredited soil mix and always make sure that you water your plants in well and you try to establish them as quick as you can.
JERRY COLEBY-WILLIAMS: It's been a fascinating visit and while this nursery operates on a truly grand scale, there are some principles that apply at home. Use good quality propagating mix, quality seed and control the growing environment and you'll be guaranteed success, whatever the size of your garden.
Information contained in this fact sheet is a summary of material included in the program. If further information is required, please contact your local nursery or garden centre.
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