Bug/Issue Speed-Gro has no effect when applied after planting

PC v1.2.33 -- The game allows you to place Speed-Gro or Deluxe Speed-Gro on a crop seed anytime after planting (and before harvest), but I just tested and neither has any effect on crop growth unless applied *before* planting a seed.

I fertilized a column of pumpkins immediately after planting, slept, then fertilized a second row, and so on for 12 days. All pumpkins were ready to harvest only after the full 13 days, as if I hadn't applied any speed-gro fertilizer.

Thanks.