Here's part of an interveiw that describes what you need to know from Dr. Schulze himself:
Instructions for making homemade lobelia tincture stronger than what you can buy.
BISER: Is lobelia inflata hard to find?
SCHULZE: Not really. Anybody can grow it. It is not the ground cover lobelia. It’s lobelia inflata, the one that has inflated seed pods. That’s where the name comes from. It does grow wild on the eastern coast and in the northeast.
Readers can always make their own tincture. If a person finds lobelia for sale, they will often find the dried stalk and a few leaves. This is the weakest part of the plant. The strongest part of the plant is the seed pods with the seeds in them. That’s what you want to attempt to find. They’re only available once a year, but if you make enough lobelia tincture you’ll have enough for many years.
You want the seed pods with the little tiny black seeds inside them. They’re so small, they’re almost microscopic. You have a dried plant that’ll have stalks, a few leaves on it, and all these seed pods attached to it, and that’s okay.
Your base would be two-thirds 80 proof vodka or 40% alcohol. Then add one-third organic raw unfiltered apple cider vinegar. That would be your liquid base, and then you would just put in your lobelia until the alcohol just covers it. Let sit for two weeks or more and filter out through cheesecloth. The acetic acid in the vinegar helps draw out the lobeline. It helps make the tincture stronger than if you just use alcohol alone. (Note: For lobelia herb, go to: Pacific Botanicals, 4350 Fish Hatchery Rd., Grants Pass, Oregon 97527. 541-479-7777)