When talking about starting seeds, most people think about spring. For annuals and vegetables that will always be true, but most people do that for perennials, trees and shrubs as well. That is because winter is considered the worst season for most plants here in the US.
Starting seed in spring means improving temperatures and longer day length. The plants will get plenty of good growth on them before they have to get through their first winter. Many of them will go dormant during this period, a defense mechanism against the cold and snow.
But what about plants from the southern hemisphere? And more specifically what about plants from South Africa, Australia and New Zealand? Those countries are the host for many of the plants that I am bringing into my garden and they very much enjoy our modified Mediterranean climate. That means dry summers. I know – you are thinking – but that is not true on the Oregon Coast. Yup. We go into drought conditions and since we are sitting on very sandy soil, the ground does not have one iota of moisture in it for a couple of months.
A true Mediterranean climate would also mean hot temperatures, but our temps are constantly modified by the ocean. We may get the odd day or two when we get about 80, but that is not common. Compare that to most of the US where summers are hot and humid. That would kill Mediterranean plants. This is one of the reasons why we see so few of these plants made available in this country. Most of the country cannot grow them and thus the major plant growers are not interested in stocking them or breeding new improved versions of them.
What I do not yet know is if our dry but cool summer conditions will enable me to grow and get many of these to bloom. That is why I am trying many different species to start with.
For these plants, summer is the harshest season and the ones that the plants have to prepare for. The best time to sow their seeds is right after the autumn rains start. Then they have the longest opportunity for putting on lots of growth, and most importantly root development before the dry heat of summer comes around. This is also why many of these plants bloom in the winter or early spring.
I did get a late start on my seed planting in 2019. My greenhouse exterior was finished in October 2019 but I still had to build the benches and the heated propagation bench. Also, my contractor is hard to pin down on when he will get to you, so I was reluctant to get too much seed in, just in case construction finished up being in the following spring.
Getting seed from the southern hemisphere does put me at a slight disadvantage in that it means I am buying 6 month old seeds and many of the choice seeds had already sold out. For 2020, the plan was to buy early and keep them in the fridge waiting for the right time to sow them.
I started sowing seed through November and December. Then I got a bunch more in the early part of the year with the expectation that I would have mixed success. For the 2019/2020 sowing season, I started 80 different species. Now you know why I needed a greenhouse and I could already use a greenhouse extension!
I will be creating pages for each of the seeds I have sown so that I can track their progress. Plus, I will take pictures along the way to see how they develop. Some have not germinated, which is almost to be expected because I am buying seed out of season. I have had pretty good success given that this is my first attempt at growing these plants which do have very specific dormancy mechanisms.
Many of these seeds remain dormant until a fire sweeps through the area. That means they would have less competition from established plants, there are more nutrients available, and nothing to shade them. Then they wait for the rains. They used to think it was the fire that broke seed dormancy, but more recently (and we are only talking 20/30 years here) they realized that it is actually the smoke. Certain chemicals in the smoke, get dissolved in water, that is carried down to the seed, and this breaks the dormancy.
Clearly, I cannot set fires in the greenhouse every time I plant a seed, and not all smoke will break the dormancy of every plant. They are still experimenting with what the specific requirements are for the smoke. Smoke from burning some plants does not work while it does for others. I import my smoke from South Africa and Australia – I kid you not. It has been captured on litmus paper or in vermiculite. When watered, the chemicals are released, and germination can start.
So, it is April and now is the time that all of the new seed is available. Unfortunately, most of it is now not accessible to me. COVID-19 has shut down many nursery operations, or governments are ruling them to be closed, or some are saying that there is no reliable air mail service and thus they cannot ensure seed viability when the journey could take a couple of months. But I have managed to find a few sites still open and willing to attempt to get seeds to me. We shall see.