Freshly picked blackberries and blueberries can sometimes harbor small grubs or worms that dislodge when soaked for a short period in a saltwater solution. Strawberries aren't commonly treated this way -- they aren't subject to the same type of pests and their unique external seeds provide protection.
Strawberries are best washed just before eating, not when you get them home from the garden. Washing them before storing them in the refrigerator hastens spoilage. Water is usually sufficient to clean strawberries.
If you're committed to washing the berries in saltwater before you serve them, just in case it will help kill any bugs or remove pesticide residue, make it a short soak and rinse them thoroughly afterward.
Prepare the salt solution. You'll need about 1 tablespoon of salt per gallon of water. Stir thoroughly to incorporate.
Remove the hulls from the berries, if desired. Keep them whole, though -- do not slice or quarter. This only makes them more vulnerable to becoming soggy.
Soak them in the salt solution for 30 seconds to 1 minute. Strawberries get waterlogged easily and their delicate flesh deteriorates. Soaked strawberries also encourage mold growth.
Rinse the strawberries in a colander under cool running water until you're sure all the saltwater is removed.
Serve the berries immediately, as part of a salad, on top of cereal or as part of a fruit tray.
Freeze washed, sliced berries for long-term storage. Freeze them in a sugar syrup or without, depending on your intended use.