Use clean plastic containers with a few perforations in the bottom to let out any excess water. Fill with a layer of minimal 5cm. of good potting soil that is sufficient humid, 6cm. for cucumber and melon.
Make the soil level and press down slightly. Put the tomato seeds on top of the soil, 1 seed in a small container of about 5 cm. wide. When using a larger container, with more seeds, put tomato-, pepper and eggplant seeds about 5 cm. apart and the cucumber- and melon seeds about cm. apart.
Cover the seeds completely with a thin layer of the potting soil and press down again very lightly.
Make de soil wet using a hand-plant-spray and use warm clean water, making sure the soil is wet throughout but not too wet, to avoid dripping.
Cover the pots with clear plastic to avoid drying out and cover the plastic with newspaper to avoid direct sun on the pots and overheating under the plastic. Put the pots ain a place where the day and night temperatures ideally are as follows during the germination period:
For tomatoes, cucumbers and melons: between 23° and 28 degrees Celsius.
For sweet peppers and aubergines/ eggplants: between 25 and 29 degrees Celsius.
N.B.: Higher maximum temperatures than recommended are very harmful for the plantlets, lower temperatures will slow down the germinating process and increases the risk of infections, notably with Botrytis.
The polythene covering is necessary to make sure that the soil remains sufficiently humid during the germination period. The plastic should not touch the plants. Because watering during that period will cause a temperature shock to germinating seeds, it must be avoided as it may kill the seeds.
Normally, depending on favourable circumstances, the germination takes only a few days for cucumber and melon seeds, one or two weeks for tomato seeds and two or three weeks for the seeds of peppers and aubergines.
Remove the paper and the plastic as soon as the two small first leaves – the cotyledons – are visible above soil level. Keep the small plantlets out of direct sunlight, after this stage the temperatures can be lowered as follows:
For tomatoes: Look for a day temperature of 23°C, 21°C on dull days and allow the temperature to rise on bright days with the sunlight to max. 28°C. After dark allow the temperature to go down but not lower than 16°C.
For melon and cucumber:The minimum temperature day or night should be not lower than 20C. Maximum day temperature 30C on bright days.
For sweet peppers and eggplant/aubergines: The best day temperature 24°C, maximum 29°C. Lowest night temperature 18°C.
The relative humidity of the air should go up and down with the temperatures during the day and night. Minimum r/h during the day and at 23C = 80%.
For cucumbers and melons, when the temperature reaches 30°C, the r/h must be as near to 100% as possible.
Transplanting the plantlets
Make sure the planting hole is moist and deep enough so that all roots can go straight down. Roots that curl up for lack of space are lost. Press the soil round the plants lightly but well enough so that one cannot lift a plant out of the planting hole by pulling on a leaf. Make sure the plantlets are not damaged by too much pressing or with fingernails.
At this stage the young plants are most vulnerable and extra attention will be very rewarding in quantity and quality fruit.
N.B.: Any watering should always be done in early morning. It must be avoided at all times that your plants enter the night when still wet.