Most types of propagation involve cuttings from various parts of the plants. This way the plant tissues are exposed to possible disease infections so you must maintain hygienic conditions in the propagating area. Always clean and disinfect if necessary your tools and benches in the propagating area and remove dead and damaged plant material. Use only fresh and sterile potting composts and apply fungicidal solutions to protect seedlings and leafy cuttings.
When you prepare pots or trays of compost for sowing seeds always lightly firm the compost using a presser board, especially around the edges of the container. Water is drawn up through the compost by capillary action and without the firming air pockets occur and the water columns essential for capillary rise are broken. There is an exception, do not firm loam-based composts as a medium filled with roots must be well aerated and have an open structure for optimum plant growth.
Always keep the compost in which plants are propagated moist but not wet. If the growing medium is too wet this will reduce the oxygen levels available and the roots may die or succumb to disease. It is important to maintain the correct environment until the plants are sturdy enough to be hardened off. Prick out seedlings to avoid their becoming overcrowded. If the air is not allowed to circulate freely through the young plants then the stagnant conditions may arise and cause damping off. Remove fallen leaves and dead matter immediately.
You must take care what potting mix you choose as the most organic potting mixes are acid with a pH value of less than 7 and the ideal range for an organic mix is pH 5-5.5. Buy a simple test kit to measure the pH of your compost. A very alkaline compost reduces the amount of phosphorus, iron, manganese and boron available to the plants. A too acid compost means that calcium and magnesium may be in short supply. If there is a need for feeding your plants always apply a proprietary liquid fertilizer and in accordance with the manufacturer’s instructions.