Question asked above.

If we know it is patented should we make note?

I do, so that people will know they shouldn't propagate it for sale or trading. Not sure what correct etiquette is. Dave how long does a patent last?

According to the US Patent and Trademark office, a plant patent expires 20 years from the filing date of the patent application.

Propagation information is useful whether a plant is patented or not. Noting its patented status is a good idea.

thank you

Thank you Dave. I have learned something new today.

My understanding is that a plant patent only prohibits asexual reproduction like cuttings or division.

If I'm right, it's always legal to collect seeds because that is sexual reproduction even when the plant was self-pollinated.

Of course the offspring are not likely to be identical to the parent, but you can select and keep crossing back until you get some individuals that you like. Then you can propagate that vegetatively to your heart's content.

Thus it is useful to know the best propagation method for some patented hybrid. After propagating it by seed for one or more generations, that method ought to be effective for your F2, F3 or whatever offspring.