Here in SE Wi we have had a fairly warm summer, in an attempt at a fall crop I planted an 8 foot row each of 4 varieties of gailaan / kailaan and 4 varieties of yu choy / bok choy. The yu choy and bok choy had nearly 80% germination in 3 days, while the gailaan / kailaan has had 0% germination after 8 days. They are in the exact same soil / light / garden and have been watered 2 times per day exactly as the yu choy.... Hmmm??? Does the warmer soil temperatures play a factor in the germination of the kailaan / gailaan?

Interesting, the gailaan planted in the spring (from a different seed source) had decent germination. I can only surmise that it has to be the warmer soil temps???

Any ideas / experience? Thanks.

I'm living in Brisbane Australia. Our summers here are humid and hot. Interesting in my experience so far kai lan are more heat resistant than bok choy.
I've never had any germination problems even in the middle of summer when temps are above 30 degrees Celsius. Getting the plants to edible size without bolting or stunting is a different story!
I wonder if it's because of the seeds. Most germination failures tend to be seed related or overwatering + rotting or the soil is too dry or cold.

Thank you for your reply. I have subsequently re-seeded the Gailaan in another bed with marginally improved germination, approx 30%, with some seedlings showing very poor vigor.

This has prompted me to formulate 11 different germination experiments which I will post later. It looks as if the "seed sprouter" and "jar" method are showing +70% success. I also have seeds in on a heat mat / under lights in peat pucks to simulate higher soil temps. Too early to tell, more later... The outside conditions have been great, 80F / 27C day and 60F / 16C night, I wish we could have a whole year of this!

My guess to the above initial post is that the seeds were possibly planted too deeply and the soil may have been a little too heavy, but still why 0% germination!!!??? Ironically as I have been trying to understand the poor germination of the Gailaan, the Yu Choy Sum is ready to eat +28 days after planting!

Have a good weekend,

John

Some of my experiments were starting the seeds in peat pellets in an idle cold frame (quicker and better germination than those under a light + heat mat). I will let those grow a few more days to toughen the stem before moving to the garden. One way or another, I will win this battle.

John