I planted my tomatoes from seed on a west-facing window sill. All the seeds germinated, and I then transplanted them into small individual pots where they continued to grow well. When the weather warmed up, I transferred them to the greenhouse and they all continued to thrive. About two weeks ago, I transferred them to grow bags in self-watering pots (pots have an outer ring which I fill with water when required). All was well until I noticed about a week ago that some of the leaves on quite a few of the plants were a pale yellow and some have started to curl inward. Could this be due to the weather turning cold? The greenhouse is fairly protected and faces south. Plants still appear to be growing well despite what is happening.
Certified GKH Gardening Expert
It could be the weather or it could be a mild case of sun scald. If the sun intensity changed quickly before the plants could adjust, the leaves will turn that pale yellow. But this can also be caused by cold weather.