One thing that has struck me with Japanese maples is the complete absence of any tags on commercially grown maple plants mentioning patents and warnings against asexual propagation of new cultivars. On most other plants, fruit trees and roses for example, such mention of patents and prohibitions against asexual propagation would be the norm, but not so with Japanese maples. I would think for expensive plants such as Japanese maples the creators of new cultivars would do everything they can to assert patent protection. Can someone explain?
Putting a patent on a plant turns off growers. That means they have to pay a royalty on each plant they grow, and most people don't want to pay anything extra for a plant. So its a financial disincentive. Plus its ridiculously expensive to get a plant patent - like $5K to $10K. Couple that with the long development cycle for something as slow growing as a JM and you have a very LONG period to recoupe your investment in the patent. There are a few that have patents, like A.s. 'Moonrise', but most people who discover a new cultivar can make more money by controlling the introduction (exclusivity) for the first few years. Plant patents make a lot more sense for annuals and other tender plants that have very short growing cycles and where the popularity of a variety may only last for a couple of seasons. Quick payback on the patent expense.
As K4 mentions there have been a few Japanese maples that were patented; Shirazzâ„¢ is one that springs to mind, it was all over mainstream UK garden centres a year or two back, and I believe was selling for quite expensive prices in the USA. Many of the best cultivars are very old and were introduced before there ever was such a thing as a plant patent, and if the new ones are not significantly better than the old ones there is no incentive for introducers to pay out for the patent fees. Example: I don't believe there is a variegated linearlobum yet. If someone was to introduce something as unique as that they might think it worth the trouble and expense to patent the cultivar.
Ryusen (or Ryusei for some folks) is patented in the US and there are talks of a couple more maples that might see a patent. I know of one maple that is currently under observation that will probably receive a patent, because it is unique and spectacular enough to warrant it. But as mentioned most growers don't want to invest in switching to a new variety over an old for several reasons, and a royalty only adds to that.
