the softwood and semi-hardwood cuttings. The soil below the trays (to increase air moisture) and the soil in the tray themselves is kept moist but not waterlogged (=completely saturated). The trays the cuttings sit in are best placed on stones to prevent capillary action (as this can keep the soil inside the trays too wet). Soil in the trays should be kept at 85 to 95% saturation. Automated (overhead) misting systems, boom systems or fog systems can be used in greenhouses. A typical misting frequency during sticking and callusing includes misting for 5–8 seconds every 5–10 minutes over a 24-hour period. After 3 to 4 days, misting is reduced to 3–5 seconds every 10–20 minutes during the day and less frequently at night. When roots become visible (stage 3) misting can be reduced, and by stage 4 (toning), little to no misting should be done (by day 10 to 14 for most species). When using plastic tents, far less misting is needed (once or twice a day). The greenhouse or cold frame should be ventilated once in a while to prevent formation of molds (manually). Air and soil temperature Air temperature for softwood and semi-hardwood cuttings is optimal at around 70° Fahrenheit (21,1° Celsius) but temperatures as low as 55° Fahrenheit (12,7° Celsius) are acceptable. Heating the air above 75° Fahrenheit (23,8° Celsius) stimulates the growth of pathogens. Ventilating (manually or through automatic window openers) the greenhouse or cold frame can lower the air temperature. Automated thermostat systems can also be used in greenhouses to keep the heat at a specific temperature. Bottom heating (soil) tends to be ideal for root initiation since growing media temperature is best maintained at 20-22° Celsius. Sunlight Whereas cuttings need to be kept warm and some amount of light needs to be provided, it needs to be kept out of direct sunlight. Some ways to accomplish this include using white wash, semi-white plastic, retractible shade curtains (which can be deployed if the sun temporarily pierces through), ... Optimum light levels are around 120 to 200 μmol/m2s at the first stage (sticking). Once callus has been formed (stage 2: callusing) and roots start to form and take up water (stage 3: root development phase), light intensity levels can be gradually increased (to 200 to 800 μmol/m2s). Most propagators find that 5 to 10 moles per day (i.e. observed using a Daily Light Integral sensor) will