What a bummer!
Now we have to switch to mustard greens and chards.
Or you can grow kale yourself.
Here's the thing, you prepare an area of loose ground and bury a few seeds and water them, boom, kale garden.
And you can get extravagant as you like with amended soils, compost, worm castings, organic fertilizers, what have you.
This is the shortest video I could find. It says exactly what you expect it to say.
Buy seeds here. MIgardener has unusual heirloom seeds as Baker Creek does except at 1/3 the cost.