Actually, you have to hope a walnut has formed.<g> These aren't the best pictures, but I hope they are adequate. If not, I have a batch of lilies going this weekend and there might be a better model in the group.
The first is the root ball of a sacrificial lily I unpotted for the purpose...you can see ( I hope) the smaller propagating tubers clustered around the main rhizome, which is mostly hidden by the roots.
Next up is a pic of my 'harvest'....pretty much what they look like when removed, but there was some washing done.
Third is a picture of the cleaned and almost ready to store tubers....and roots and leaves are removed and they are left a while to dry.
What's left in the fourth picture is the plant proper....there is nothing there that is going to store easily....I have the luxury of repotting it and from what I have been told a large lily isn't easy to over winter.
Lastly, is one of the mesh bags I will store the tubers in....I think Caladium bulbs came in it.
How to get the walnuts? Well, since the thread drifted a tad that way, I 'll go with the flow.<g> Planting in small pots and stressing them further by under feeding them is one method commonly used. Some lilies it works and some it don't. If you choose to go that way, what fertilizer you use has no bearing on your success, as long as you are familiar with the mechanics of it. Tabs you can stop on a week or two's notice...though some, like Agri-Tab, claim to be a longer controlled release tab fertilizer. Osmocote, if you know your water temp, you will know how far in advance to stop feeding. I have a commercial grower friend in TX that uses Nutricote and he stops feeding in May/June, but then he understands how long Nutricote will last in his ponds. Frankly, depending on the length of your growing season....August may be too late to stop and still get good tuber formation. Many people will grow two or more of the same lily; some for show and some for tubering.
I use a different method to tuber...letting the lilies dry out. I think it works better,as again, it mimics their natural trigger, but it is more risky or at least more labor intensive.
Truth is not what you want it to be; it is what it is. And you must bend to its power or live a lie.”― Miyamoto Musashi
"Knowledge speaks, but wisdom listens." ~ Jimi Hendrix
“The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.”― Stephen Hawking
Craig