It may not have been a part of her garden then but we don't know that for sure. Seen here from the back of G3 Wysteria's house The card's info says:
My Little Pony Wysteria's Garden
EARTH / Plant / Level 4 / ATK 0 / DEF/ 2150
This card cannot be Normal Summoned or Set. This card cannot be Special Summoned except when you control "25th Anniversary Celebration". This card cannot be destroyed by battle. Once per turn, you can draw 1 card. You can only control 1 "My Little Pony Wysteria's Garden".
2 years, 1 month ago
11 Jul 2016 14:41 CEST
Full Size: afb15f1909303d7e221608546163e7dc