[milkman]

I always grow spinach beet and chard in place of spinach, as on my chalky stony soil the only excuse it needs to bolt is to be sown!  

the beet and chard never bolt and self seed quite readily the following year if you let them go to seed which looks quite dramatic.

and the guinea pigs love munching on whatever bits of the plant we don't want to use in the kitchen.

[Growbag]

I always grow my spinach in a 29 cm pot in the greenhouse.   I get lovely soft leaves for about 6 weeks or so before it bolts.   Tried sowing in the ground but it was futile.