I usually sow our tomato seeds at the beginning of April. This year was no different as I sowed our seeds on 08 April. We don’t have any heating at all in our greenhouse so in order to get quick germination the seeds are placed under a growlight situated in a spare room indoors.

This year I’d been given some extra seeds from a friend and I decided to try a little experiment. If these seeds were sown and left in the greenhouse, firstly would they germinate and secondly, if they did how long would they take.

 The seeds inside germinated within a few days and as you would expect there was no sign of any germination of the ones in the greenhouse. After a couple of weeks the ones inside were almost ready for transplanting into larger containers and with no signs of anything happening in the greenhouse. I’d decided that the greenhouse sown seeds weren’t going to germinate.

Then when I’d almost given up on them, the greenhouse sown seeds germinated. These are shown in the photo below.

The rate of germination has been pretty good considering the low temperatures they will have experienced in the greenhouse with only a couple of seeds failing to germinate. I’ve included a chart below giving some idea of the temperatures both inside and outside since sowing the seeds.

Whilst the inside temperature range will be pretty accurate there will be some large inaccuracies in the greenhouse temperature range based on outdoor temperatures. The low temperatures will be about right as I know there’s not much difference in the temperature inside the greenhouse and outside on a cold night. However, daytime temperatures in the greenhouse soar up to the 30°C mark or higher on a sunny day.

It will be interesting to see if there is an obvious difference throughout the growing season due to the way the plants germinated.