Milk Thistle Production in California
Answered by: Rick Miller
Question from: Susan Calfee
Posted on: February 04, 2010

We have 90 acres in Tuolumne, CA, near Sonora. about 10 acres are flat and I have just realized that the plant we have been paying each year to have sprayed and killed, is Milk Thistle. How can I get information about possibly turning this into a commercial milk thistle farm, even if only on a small scale. It definitely grows WELL here.

A weed is a "plant out of place," one which cattle won’t eat. The reason this crop is classified as a noxious weed is because of the thorns and the cow’s soft pallet. It is the seed from this thistle which is marketed. At one time, this thistle was confused with others (like Russian), because they tend to look similarly, and had similar biblical references. With more careful observation one can notice distinct differences in the diverse thistle plants, include their distinct air floating seed

Originally from the Mediterranean region in Europe, today milk thistle grows and thrives in natural conditions all over Europe as well as in California and Australia (now classified as a noxious weed). Milk Thistle grows best and flourishes in uncluttered regions. It requires a sunlit position and self-seeds fast. Currently, Milk Thistle is commercially grown as a decorative plant.

The flower heads are harvested when they are in full blossom during the early summer season, while the plant’s seeds are collected in late summer. Because it grows in warmer climates, its seed tends to also cluster larvae from the previous winter’s Mediterranean Flour Moth. The seed usually either requires an insecticide, or be sterilized after harvest. This is the primary problem with cultivating this crop.

And, this is the primary reason there are now shortages on availability for COG seed, and the upscale manufacturer uses for silymarin products. Import prices have increased to almost $8.00/lb, FOB, with a need now for more than 2,000 cultivated acres in North America. Total world production is now down to less than 12,000 acres, with an annual; growth curve need of more than 2,000 new acres each year.

That makes this a very interesting crop for domestic production. The flower heads will most likely need to be taken by hand, and then the seed gassed, or somehow fumigated for the larvae. How this might be done may require working with a certification board (like the State of California, at UC Davis). In California, I would suggest try working with their Small Farm Center, My guess is that the larvae is a common problem with other seed crops, and there may be some alternatives now available for consideration.

Lower Baja (Mexico) Peninsula was a primary source for years with this crop, but got hung up with this larvae problem (and hence, the COG need). That’s when shortages began to show, with such countries as Israel becoming a primary producer. Now, with growing demands, organic manufacturers have trouble locating "clean" seed that does not require sterilization.

There is now even some opportunity to export this to larger European markets, with the advent of a flower head harvester. With a generic harvester, a number of flower head crops become feasible for export (like Chamomile, Red Clover, and Pyrethrum).

By the way, even with exceptional crop yields, harvest techniques, and the elimination of insect problems, one pound of seed requires a huge volume of work. The seed itself is very light, and difficult to manage without some advanced technology. This is another reason why there are world shortages now. Most farmers are not willing to put this kind of effort into competitive returns, and having to work something by hand.

Before you actually consider this as a cash crop, be absolutely sure of your returns from the labor effort. It is very difficult to compete in this crop without some technological edge. Before I would personally consider this as a project, I would think about how the seed might be taken by some existing form of technology.

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