I've kept hips for several years and the seeds still germinated for me. You can try soaking them but it might not help. Rose hips are very hard. I just use a good sharp knife an cut them open. Don't worry about cutting the seeds, they're even harder than the hips! After you get them out of the hip clean them really well to get all the bits of hip material off of them. It's thought that there is some kind of enzyme in the hip material that inhibits germination. I put them in a fine sieve and scrub them against the sides under running water. Again, this won't hurt them. Then you can soak them in some hydrogen peroxide for a few minutes. This will keep some of the mold down. Wrap them in a damp paper towel, seal the towel in a plastic zip bag and put them in your fridge for a few weeks. When you check them don't be worried if there's mold on the towel. It doesn't hurt them and there are some studies they say certain molds aid in germination. If they've germinated you'll be able to tell easily. The little greenish white root will be sticking out of the seed. Carefully get the seed out of the paper towel and put it in seed starting mix. If you have starter trays that works best. If not start it in a cup but make sure it's starter soil not potting soil. I don't pot up to potting soil until they have at least 2 sets of true leaves. Put it under lights if you have them. If not in your sunniest window. Like the others have said it will not be "The Doctor" but it's own new variety and depending on how it was pollinated can look behave totally different. Have fun!

Sophora affinis aka Eve's Necklace

I don't know if you guys have ever gotten a response to this, but that's a water chestnut seed. They were my favourite part about growing up near the lighthouse in Saugerties. =) Here is a link that might be useful:

I know of a grower who sources their seeds from some trees north of McKinney that are at least 30 ft. They were said to be very common down around the Cedar Hill area but are rare now.