Wait until the seeds have matured/ripened on the tree. This happens from Summer through Fall, depending upon your location. Some indicators that the seed is ripe will be seed-cases that are full-size; seed-cases that have begun to turn from green to brown; and evidence that other seed-cases have begun to fall from the tree. Many people prefer to harvest seed before it is fully dried on the tree. I take handfuls of seed and throw them into a small cardboard box to finish drying. I don't leave them in direct sun. Now, the final caveat: I've never grown maple from seed before; but I have collected seedlings from seed sown outdoors the previous Autumn. Next Spring, I'll give my collected seed a try. Josh

I don't like the idea of moving a Japanese Maple in summer. If you live in Texas, you are in a location that is somewhat stressful for Japanese Maples (which are native to the mountainous, alpine areas of Japan). In their native habitat, they are used to living in areas with lots of water, fairly quick-draining soil, and fairly cool temperatures. I live in the Pacific Northwest, which generally is a great climate for these trees, since we have two of the above (quick-draining soil and fairly cool temperatures) in abundance here. Ironically, what we don't have here is a lot of rain for about a 3 or 4 month period during the "dry" season (at Seattle's airport, there hasn't been measurable rain in 25 days). Living in Texas, the stresses you are going to have on a Japanese Maple are 3-fold: 1) heat 2) excess sun; and 3) wind. In siting your tree, you are going to want a location which gets a partial but not total sun exposure. It's especially important to protect the tree from the hottest sun of the afternoon. Also, ideally you want some type of "windbreak" (the house, a fence, even natural hedging or other plants) that can protect the tree from at least 1/3 of the winds it can get, preferably the strongest, prevailing winds. I have 6 different Japanese Maples in my front yard. I water them, generally, 1x a week, with a hose. They are flourishing (I have acquired all of them in the last 4 years and they all have seed pods, except for 1). I don't fertilize them. They are flourishing because they are well-sited--none of them get significant afternoon sun, and they have good wind protection (two of them have about 300% of the 360% of wind protection, for example, my house, the neighbor's house, a fence, and neighboring plants protect them from all except NE winds). Good luck. My personal preference is not to move plants in the summer, particularly in an area with a continental climate (I used to live in Wis. & Maryland)!!

Please ignore "Mike's" post. We all learn as we continue the art of gardening.. The link offered is a genuine respected gardening site. If you would like I have a great site for purchasing a wide variety of different Japanese Maple seed. It will be important for you to do some research so they will be grown in the correct zone. I live in zone 5a, but with winters that are too mild, it creates a difficult situation for growing any type of JM. Lets do our homework and maybe together we can come up with a inexpensive way to propagate JM seed.

I think that is a VERY bad idea...there is NO reason to believe the root stock is special from one new growth branch ......you can buy 10 red Acer palmatum generic seed growns for what one nice Seiryu may cost. Both green and red A.P.'s are used for root stock the latter a bit more rare since many growers can sell them to umknowing folks for biggeer bucks than the green even though they most likely will be ORDINARY...Ideally they should match but most growers are too busy, lazy, or just don't care.... and the green is always much cheaper especially larger diameter RS for the same reason above they can sell them for 25$$ or more in 3-4 years. Whatever keeping an unknown and throwing out a Known cultivar is at the very least ignorant and very short sited IMHO...But one persons decisions may be so while anothers is otherwise ...that is my opinion but it is not my tree , decision and I am NOT infallable so make your own choice!! David