Can you use bat guano all the way into harvest?
Generally, you need only apply it during planting but as long as it's been properly aged/composted, I don't see why you couldn't use it throughout the harvesting season, as needed. That being said, you may want to wait till season's end (fall) and then turn it into the garden plot once it's been cleaned out. This will help replenish the soil with nutrients as it sits over winter. If you have not yet read it, here is more information: https://www.gardeningknowhow.com/composting/manures/bat-guano-fertilizer.htm