Well, you do wait for your flowers to grow to get moshlings on Moshi Monsters. Although, some combinations do not get you moshlings.
If a moshling is not listed in the Moshling Zoo, then it has not been released and you can not get it. You need to wait until Moshi Monsters releases it.
There is no Bessy moshling on Moshi Monsters.
There is no Christmas moshling on Moshi Monsters.
There is no squirrel moshling on Moshi Monsters.
No, there is no hamster moshling on Moshi Monsters.
There is not Moshling called Stingy on Moshi Monsters.
There is no moshling named McNippy on Moshi Monsters.
There is no moshling called Diamic on Moshi Monsters.
There is no Stringy Moshling on Moshi Monsters at this time.
No, there is no Moshling named Boney on Moshi Monsters.
There is no Moshling named Libby on Moshi Monsters.
As of May 2013, there is no moshling with the number 26 on Moshi Monsters.