Yeah, I'd burn an entire season of crop yield at this point for it, but if no artifact it's useless to me.
If it's any use I did some more reading around and it seems the most common places people are saying they found it for the first time are in the first 30 levels of the mines as loot drops or in the fishing treasure boxes that come up during the mini-game. Ultimately it's still RNG and unless you alter the game to give yourself what you want, you're at the whim of RNGesus.
Yeah after my daily farm chores I'm running through floors 20-23 because there's a lot of monsters/boxes/loose soil, and I've gotten so far 5 more lost books and at least 20 other artifacts (probably only 5 or 6 unique, but TONS AND TONS of repeats)
Yeah, that would make sense. Maybe it's a bug? Because I'm 100% certain I received the artifact and not the seed packet.
I got 2 ancient seeds from the seed maker when I was making seed for next year'd cranberry crop. I've gotten 2 after 3-400 seeds so that fits with the 0.5% chance I saw stated earlier.
Found one just a bit ago in the mountains (that hoe'd spot to my left, took me a sec to realize what I just found).
I found one on floor 20 of the mines while cave fishing. It popped up in a treasure chest I caught while I caught a fish.
The ancient seed grows in spring, summer and autumn. It's best to plant it in spring, though, since it will keep giving you fruit until it withers away in winter.
That's exactly what I am planning on doing, but it takes sooooo long, when each plant needs 28 days to mature. I've got one just about ready to produce it's first fruit, and I got one that I started half a season ago and that's it. But dude, I figure if you can get at least 110 AFs (the greenhouse will fit 120 but you probably want sprinklers), that's anywhere between 82,500g and 123,750 every 8 days for basically doing nothing except picking the fruit. In fact, since it takes 8 days to grow, you could even get a bunch of wine kegs or preserves jars and get even more stinking money.
I have 96 ancient fruit plants in my greenhouse. Ancient Fruit Winery is really the way to go for greenhouse money...
If I remember correctly, you can get it from the wandering merchant too. I think I got my 2nd one from her, first one from mining... which unfortunately got struck down by lightning lol