Research has shown that eating a lot of fruits and vegetables tends to lower BP. Fresh ones are usually best, to avoid the extra sugar in canned fruits and the salt usually added in canned vegetables. Frozen ones are sometimes okay, sometimes not; you have to read the label. Celery is supposed to be particularly good; it contains a weak diuretic, but as I understand it, you'd have to eat about four whole stalks of it to do much good.
I've personally found that my BP always went down after eating fresh asparagus, but I don't know if that's just an individual reaction or if that typically happens to others. I also know that a huge luncheon salad with a raw spinach base and foods like broccoli, cauliflower, celery, carrots, asparagus, mushrooms, radishes, bell pepper, and garbanzo beans topped with maybe a small amount of tuna or chicken or ham will keep my afternoon BP lower than a sandwich luncheon. Be sure to include a little bit of fat with the salad, though. I use a full-fat salad dressing, but keep the quantity down. A reduced-fat dressing would probably be better. But a non-fat one wouldn't be good unless you had other fat in the meal. Fat is required to help the body absorb the nutrients in the vegetables.
You might want to start doing some experimenting with taking your BP before and again one or two hours after meals and see if you can determine which foods seem best for you. I'm sure there are individual differences.
Here is what i read in a diabetic mag for foods to help lower bp and stroke risk: cherries, dried apricots, oranges, green peppers, cucumbers, spinach, broccoli, sweet potatoes, celery, and squash. Cayenne pepper, curry and black pepper are the seasonings to use to lower bp. One must have two servings daily.
I also have a list of foods for diabetes, which was dx'd in Mar. 05. I've tried this and have very good bp at 108/65 and im 31yrs old, male.