As I mentioned in my last piece, seeds which are sown early in the year really need to be placed under lights if they are going to thrive. As amateur growers we get excited about sowing as soon as possible in the year when it can often be better to wait a few weeks until light levels are much longer and brighter. The other point to remember is that sowing can be done in a confined space but as soon as the young plants are through and ‘pricked off,’ they will require much more room. This in turn requires heat and off course,expense.
Above is a picture of our propagator which has thermostatically controlled heating cables and a tube heater at the rear. Two fluorescent daylight reflector tubes hang just above the propagator itself and are on for 16 hours a day. Fluorescent light is the nearest thing to daylight and is ideal for most plant species. Reflector tubes make sure that the majority of light shines downwards onto the plants.In the foreground is a max/min thermometer just to keep a check on the temperature extremes within.
The other picture is of tomato seedlings which have been under the lights. These are sturdy plants showing very little signs of elongation and are now at the stage for ‘potting on.’ Once potted, the growing temperature is reduced somewhat and tends to match the natural light levels, so keeping the plants in good condition. Always remember that your glasshouse heater must be able to cope with the coldest of conditions and that all electrical equipment is water resistant.