Pot and tub seedlings, whether sown or from cuttings, grow stronger if they are re-potted in a plant container of suitable size and earth whenever required.
Plants sown in a sowing dish are re-potted for the first time when the first three to five leaves have developed after the previously appearing seed leaves. The same applies to freshly rooted cuttings in cutting dishes if they are sufficiently rooted and have begun to sprout.
Then remove the individual plant from the soil with a dibber and shorten the roots to about three to four centimetres in length. Place the seedlings, again with the aid of the dibber, in a 9 cm pot with good quality potting soil.
Loosely fill the pots up to the edge with soil, make a four to five centimetre deep plant hole with the dibber and place the seedling in it so that all the roots are in the plant hole and no roots are bent. Now press the plant earth down at the roots so that the plant stands straight and firm. It should stand as deep as it was in the seeding or cutting container. At the same time, the volume of the soil should be reduced by pressing slightly, so that a so-called pouring edge is created between the soil surface and the pot edge. This prevents water and soil from sloshing over the edge of the pot when watering and thus soiling the surroundings.
If the roots of the seedlings have completely gone through the size 9 pot after a few weeks, they are re-potted into larger pots, for example size 12 or 13 pots, then in even larger pots (for example size 15 to 19 or larger, depending on the plant type and its growth rate) or in the planned use in the garden bed or plant pot.
Tip: Unlike cheap soil of lower quality, high quality potting soil is mixed so that it is of a stable structure, is moistened better when watering, is pre-fertilised and contains a high percentage of clay. For use with plants which prefer a mineral soil to one rich in humus (for example oleander or also potted palms), also mix a third of expanded clay or pumice stone or lava stone into the high quality potting soil.