Thinking along the lines of ‘cole crops’/crucifers/brassicas kale might be more tolerant than most and also garden cress. There’s evidently a demand for a more cold-temps-hardy cress because research is being done in that direction. But other than those two presently in C&G’s lineup I don’t think there are any besides the lettuces.
At lower temps it is worth to try (in addition to the plants mentioned above) arugula, leaf mustard, red leaf beet, romaine lettuce, green sorrel, bloody sorrel and the newest plant pak choi. From herbs dill is also good with somewhat lower temps.
Thanks but I’m forced to stick to innocuous leafy plants and some herbs now.
So instead I’ve focused on salad
greens and a few common herbs. The romaine, green leaf lettuce, dill, thyme, and bloody sorrel have done very well. I have just one nice almost-ripe yellow sweet pepper from a mid-December experimental planting, so they probably do much better in climates
like Singapore enjoys. And I’ve got dandelion seed for the summer for greens in the experimental pods.