Bunch of ways to handle that chore. Essential elements are brisk air flow and some way to keep the bugs off. Electric food dehydrator works well. Electric home oven can be used. Trick is keep the heat at 140 or less. Normally accomplished by setting the oven as low as it will go..and propping the oven door open to the first notch. Keep a small fan blowing on it helps a bunch too. Need to move the goods around a bit so it dries evenly..remember its a drying process..not a cooking process. When you move into lighter colored stuff it helps to dip in ascorbic acid or vit C to keep it from discoloring. Kale is green already I think so shouldnt hurt to discolor that. Best of fortunes. Dehydrating stuff is a lot of fun and is a good way to store up food for when Obie wrecks the economy.