Firstly, please check that you have added the correct amount of water into the tray at setup. It should have been 550mL. Click here to watch the setup video.
If there wasn't enough water at the start, germination will be patchy as the seeds have not had access to sufficient water.
We have tried to select seeds with similar germination times but there
are some varieties which are slightly slower to start (especially during the
colder temperatures)
The Rocket, Mizuna and Kale are fast germinating while the Pak Choi and
Mustard may take a little longer. The Cress takes the longest at about 16-21
days. It's best to plant similar germinating varieties
together.
If one side is not germinating as well, please leave the lid on a little
longer for the weaker side to catch up. However, even if the lid is removed
early, the slower side will eventually catch up given the right temperatures
and sunlight.