The Smoldering Seeds are a seed added by JuiceWares. They grow a Blazeflower, when planted onto Soul Sand. Blazeflowers grow very slowly, however their growth can be sped up by placing a lava source underneath the Soul Sand they are planted onto. For each growth stage, there is a 1% chance that the lava source will be turned into Obsidian. If rained on, the plant will die.
Smoldering Seeds are obtained by breaking Blaze spawners.