Week 3; A combination of low temperatures, high humidity and poor air circulation, can cause problems under glass.
Discolouration of leaves may be caused by low night temperatures (red) or fumes from paraffin heaters and poor ventilation (yellow)
Good ventilation is essential, where gas and paraffin heaters are used, as both generate high volumes of water vapour, and traces of toxic gases.
Keep plants on open staging surfaces such as metal mesh or timber slats, to improve air circulation around and through the plants this should reduce possible attacks of grey mould disease (botrytis).
Week 8-13; On bright days, temperatures can rise rapidly under glass, so make provision for adequate ventilation.
Week 18; Ensure your greenhouse or frame is adequately ventilated.
If you can not be on hand to open and close vents as weather conditions change, fit an automatic vent opener.
Louvered ventilators can prove quite useful as well.
Week 23>; Things may be getting quite busy in the greenhouse at this time of the year, not least the need to keep temperatures and humidity in check
Some tasks that might need regular attention are;
The need to open vents early on warm, sunny days, automatic vent openers will help with this task.
Damping down the floor to raise humidity and reduce stress to plants through lack of water, automatic watering systems and capillary matting will help with this.
Fixing shade netting, a roller blind type will make this chore much easier.
Week 50; Keep a close watch on minimum night and maximum day temperatures and adjust greenhouse heating and ventilation to avoid drastic fluctuations.
A max/min thermometer is essential to keep an accurate record of temperatures.