Over the last four years I've been working on the problems with farming the wild lettuce. Wild lettuce is notoriously difficult to grow in a field from seeds. The old timers observed this as well.
The main problem, in regards to field planting, is the way lettuces propagate in nature in general. They produce an enormous amount of seeds because in the end, only a few of them will come up. The seeds fall in the summer, but the summer heat is not conducive to easy germination. It becomes a game of survival as to how many of the seeds actually make it to germination, and how many of those plants survive long enough to become viable contenders. There's also the problem that water is essential, and a dry fall can further contribute to the problem.
The plant manages all of the variables presented by nature through periods of dormancy, and with a deep tap root that keeps it hydrated during dry times. This means that if that plant is stressed, it can stay small for a few years, or even the seeds themselves can remain dormant.
Lactuca serriola has it a little easier, because its growing cycle is much shorter. It can also germinate in the fall and come up in the spring, but lactuca virosa has a tendency to stay dormant much longer. This can result in a crop of virosa skipping an entire season before bolting. It will remain a small rosette until the time is right. I'm pretty convinced that under the right conditions, one could plant serriola from seed in the spring and it would bolt by summer.
Serriola will come back for several years, and will keep getting bigger and bigger. Virosa also comes back, but it loses the original stalk, and instead one will get a very bushy plant full of flowers. It is also possible to cut the stalk of a virosa about a foot off the ground and many smaller branches will grow from it the following year.
I have seen L. virosa altissima in France that was so large, with a stalk like a tree, that it surprises me something that big could grow in just two seasons.
This year I did an experiment to seed the field with French L. virosa altissima. I did it in the dead of summer, around the same time as the plants go to seed. The idea was to sort of follow its natural life cycle. It will be interesting to see how many of them come up in the fall. I doubt hardly any of them will. Every time I’ve tried to field plant with minimal care as to watering and conditions, it has been a flop. But this was the point of experimenting with direct sowing, to see how easily or not easily it would come up if one simply drops seeds onto the ground and waits for germination. The answer is, of course, not easily.
What I am working on is the best method for field planting without having to spend millions of dollars to keep them alive. I think one could field plant them from seeds in the summer with the use of a very soft potting type soil. It would require a precision watering system, and shading tents during. I find this quite impractical for a large field crop, unless one has a lot of money to play around with.
I have had much success, however, with transplantation. While this method requires more effort, it is an excellent way to grow wild lettuce.
Under only slightly controlled conditions as to watering, I was able to get a pretty large crop in my seed garden using transplantation. I transplanted them quite late in the fall, and a majority of them were still able to bold by April.
I did the same thing in the large field in the fall of 2022, with less optimal conditions. They are still waiting to bolt. I am very confident that next spring they will be massive, having been around for three seasons already.
This has always been the challenge with virosa. The growing cycle takes years. To do it correctly requires many seasons to develop a cultivation. This, and the difficulty in harvesting lactucarium, certainly led to wild lettuce losing favor as a pharmaceutical crop.
There is one method for planting in a garden, which I have heard called the volunteer method. Given the challenges of growing Lactuca virosa, the old timers used the volunteer method as well. A few seeding plants can produce quite a few "volunteers" around the mother plants. The old timers would simply dig up these small plants wherever they found them and transplant them where they needed to be. This can be done at various times of the year. Volunteer plants should be quite small, as the tap root should not be broken. One can dig up a kind of plug, keeping the soil around the root, or simply digging out the plant. So long as the roots are not disturbed too much, either method will work. In my opinion, the plug method does work better.
I have found that what I call English virosa, common lactuca virosa, to be perhaps even more tedious. This variety is readily found around the countryside in the UK. It has deep purple colors on the stalk and leaves.
This coming year I should have enough English virosa to begin selling the seeds on the shop. We get so many messages from people who bought seeds online, only for them to turn out to be some sort of thistle. I will end this tyranny!