How do I breed a Seasonal Dragon in DragonVale?

Looking for the fastest breeding combination to hatch a Seasonal Dragon? This Epic Dragon dons a new outfit for each season, and looks truly awesome, so it is worth the struggle of breeding it (which is a challenge). All of the details are below:

Seasonal Dragon

Breeding Pair: Blazing + Cactus OR Poison + Sonic

Breeding Time: 48 hours or 38 hours 24 min (with upgrade)

Availability: Unlimited

Type: Seasonal

Price: 2,000 Gems (insane )

Note that while Flower is normally a good substitute for Poison, it is slightly less good while the limited Rose Dragon is available.