When you say little red spiders... could you possibly mean spider mites, with two red-like dots on their backs? Because if they are truly spiders of some sort, I have just never heard of a spider eating your plants. If you see a webbing, they are spider mites. With this in mind, good luck... nothing that is simply "organic" (whatever that really means) is going to address your problem, and you have a big, big, big problem with sm populations growing. If sm's, do a search & you will find a sh**-load of info & peculiar fixes. Best.