Big problem with outdoor grows Big problem with outdoor grows is that the black market is growing Cannabis males outside to curb personal grows and that inadvertently effects all outdoor grows because you have to harvest the Cannabis before seed production. Plus personal outdoor grows now are mainly novice for fun growers a that don't scrutinize their plants for males and are allowed to grow. Cannabis pollen will be a problem for LP's greenhouse operations in the late summer and will have to filter incoming air to prevent seed production.