Remember when Tom Sawyer had to whitewash the fence? Whitewashing the fence used to be a spring cleaning ritual, like beating the rugs or washing the windows. Since it's safe enough to use and will wash out of your clothes and off almost anything else, the young folks were often involved in doing it.
Whitewash isn't really paint and it won't stay on as long as commercial paint, but it isn't laced with chemicals and it won't drain your pocketbook either. It's safe for barns and around small animals, too. Besides that, it can be fun to make your own without relying on the store to get what you want.
Remember that whitewash is a wash, not a paint. If you lean against a whitewashed fence or wall, it will leave a chalky residue on your clothing. Whitewash isn't good for places that get wet, as it will eventually wash off; that's why Tom Sawyer's fence needed whitewashing every year.
Making it isn't too hard and you can still find the raw materials easily. The first ingredient is lime. Buy hydrated lime from a builder's supply store if you can because it's much cheaper than the lime you will find in garden centers. Lime is caustic and you shouldn't get it on your skin or in your lungs. A pair of rubber gloves and a dust mask as you're handling it will keep you safe.
Besides lime, you'll need salt, a bucket and water.
To begin the process, put about four cups of lime in a bucket (it isn't science, so "about" is sufficient), add about a pound of canning salt and mix them together then you're ready to add water. It will take about two gallons of cool water and although some people use hot water, it isn't necessary because when the water is added to the lime, it will heat up.
Begin adding water slowly, mixing it into a paste at first, then gradually adding more until you have a slushy mixture. Keep stirring it while adding water. When you've added enough water to make the mixture a thin liquid, you can put in pigment if you like, but whitewash is white and will dry that way, so unless you want another color, you're done.
The mixture can be used immediately but it will be fine if it stands for a day.
Use a long bristled brush or mop to apply the whitewash. It probably won't look as if it's covering very well, but it looks better as it dries to a chalky, bright white. Who knows? You might enjoy whitewashing as much as Tom Sawyer's friends!