hi dela! canned: no way. frozen greens: no, not the same. i will use frozen berries as a backup for add-ins to a green smoothie, but not for the greens. frozen isn't the same as fresh. when you freeze food, whether fruit, vedge, or meat, the water in the tissue expands and bursts the cells. they just aren't viable after a defrost - imagine if you did the same thing to your hand. no, the magical benefits of a live green smoothie are in the living enzymes & other nutrients, that face that they have not been damaged or deteriorated due to the trauma of extreme heat or cold. use cheap greens if it's an issue -- get parsley, dill, cilantro, or collards, instead of spinach or kale. parsley is a fave in my house for the very reason is that it costs a fraction of what organic spinach goes for. have you tried a green smoothie yet, dela?