Preheat oven to 400 degrees F (200 degrees C). Spray a 9x13-inch rimmed baking sheet with cooking spray.
Spread beets, white potatoes, turnips, carrots, sweet potato, and red potatoes in a single layer on the baking sheet. Drizzle 2 tablespoons olive oil on top. Squeeze lemon juice over vegetables and season with rosemary, thyme, coriander, cayenne, salt, and pepper.
Bake in the preheated oven until root vegetables are just tender, about 45 minutes.
Heat remaining 2 tablespoons olive oil in a skillet when root vegetables are nearly done. Cook and stir garlic over medium heat until fragrant, about 1 minute. Add kale; cook and stir until bright green, about 5 minutes. Season with sea salt and mix into the root vegetables.