Which color? I believe the yellow and brown piles are available now via balloons, and the red pile will come online later in the fall when the maple leaves start to fall (mid-November). The green pile DIY is available in the spring for Northern Hemisphere players.
You’re welcome! Yes, watch out for the balloons— most seasonal recipes will drop from them, although on rare occasion a villager might also have one (I don’t generally have as much luck with seasonal recipes from villagers, however).