I had a LOT of secret gardens as well. Every ?-8 I did so far spawned one, and Phase 2 overal gaining me about 700 dumplings just today. Which means I'll reach 4,000 dumplings in about 3 days. So when I break 3,500, I'll stop doing the Secret Garden, and just use the stamina to run 14-1 or 14-4 instead, I didn't 3-medal either yet, and those can spawn either SG or a Raidboss, which appear in short supply as well now.