Aged garlic took mine down. I don't have hypertension so I got off of it; my BP returned to my normal. The studies are actually kind of hit and miss, but it worked for me as a normie.
Another one to look at is pomegranate. A friend of mine was having side effects with his BP medicine, and I made the suggestion to try it, LEF brand pills or POM juice. He was able to get off, had same BP as when on meds, without side effects. There are lots of studies to look at on this on at pubmed, essentially a beta-blocker with some other actions.
Lastly, most people are deficient in potassium. Get some potassium glutamate powder to supplement (not pills as they are regulated to be under 100mg). RDA is 5g, and most people are under 2g a day intake. I have taken 500mg worth of potassium, daily in water, for years without issue.
It loses some actives and gains as well as intensifies others. The studies are not consistent for its ability for dropping BP. For whatever reason, I see a drop when using it and a rise to normal when not (did this twice before isolating it as the cause, for me).
If I was looking for supplements for BP, based on research, I would go with pomegranate or potassium.
I haven't tried garlic, however I have had very good results supplementing with Magnesium (I use the Citrate form). New research has verified the efficacy of Mg as well, see http://www.sciencedaily.com/releases/2012/03/120313230354.ht..., for example. It also has a positive effect on testosterone!