Foods rich in Vitamin C, Vitamin E, magnesium, calcium, potassium, monounsaturated fats and omega 3 fatty acids help lower blood pressure.
Foods to eat include all leafy greens like kale, spinach, romaine and chard, beets, broccoli, asparagus, cabbage, celery, crimini mushrooms, onions, garlic, almonds, avocado, walnuts
rice bran (rich in magnesium and many B vitamins), strawberries, kiwi, tomatoes, papaya, raspberries, oranges, bell peppers, potatoes.
In addition, foods with a diuretic effect (cucumber, lemon, celery, beets, cabbage, parsley, tomato, watermelon, asparagus) have been shown to help.
For those taking Coumadin or certain blood thinners it is important to keep a consistent intake of Vitamin K so that your Dr. can adjust the dosage of your medication. It isn't necessary to avoid vitamin K containing foods completely, but more so to make sure you eat the same amount daily.
Here's a list of vitamin K content of various foods: