Plant propagation: Part 1


Notes from Urban Veggie Gardening Workshop # 4

There is so much magic in a tiny seed. Dormant, still, silent: the seed speaks of an unimaginable potential.

One of the most exciting aspects of our work is gardeners is to germinate seeds and generate our own seedlings. Not only is this much more economical than purchasing seedlings it also gives us a chance to grow unusual varieties that are not available commercially. So what’s the magic, and how do we do it?

  • Each seed is actually a plant embryo that has a small food package attached to it. – Getting a seed to germinate involves keeping it moist, keeping it at the right temperature, ensuring it has some oxygen, and in some cases also providing light.
  • Some seeds have very tough cases and these may need to be scratched with a knife, or soaked for a few hours in water.
  • It is most important to use very finely sifted soil and press the soil down firmly in the germination tray. Lumpy soil creates difficulties for the tiny roots that emerge from a seed. Course soil that has large air gaps does not provide an evenly moist environment.
  • It is important not to plant a seed too deeply. The smaller the seed, the smaller its supply of food. Small seeds only need to be a couple of millimetres beneath the surface with a fine dusting of soil on top. Very large seeds such as broad beans may be 2 cm down as they have plenty of food to work with. If a small seed is planted too deeply, it will never get its head up into the daylight.
  • Since a seed is a plant embryo, the first leaves that emerge are actually part of the seed itself. The second picture shows you the new ‘seed leaves’ of a Tommy toe tomato. They pop out of the seed and at the same time a small root finds its way down into the soil. Imagine how difficult it must be for a seed that has no roots so it can’t feed and no leave so it can’t create energy from the sun. Fortunately the basic essentials are built into the seed itself, so provided the seed is kept moist and warm, these tiny roots and seed leaves will come out.

The seed leaves are not true leaves, but as they grow, they generate true leaves. You can then see some of the characteristics of the emerging plant. In the third picture you can see Tommy toe tomatoes that are ready to be transplanted into the garden. The tiny seedlings with their little seed leaves in the picture above have been carefully removed with a teaspoon and placed into separate 10 cm pots. In this way it is easier to keep them moist and well fed until they are large enough to plant in the Garden here. Unless they have substantial roots and well-developed stems and leaves they will not survive here, since they are exposed to full sunshine, and watering which is not always as regular as it needs to be. While the infant plants are maturing in our backyard, we keep them under a plastic or mesh structure, raised up on a the tray, with plenty of snail pellets on the ground around the base. Young plants need to be protected from strong rain strong wind and pests, such as grubs, snails, and sometimes even possums.