EDIT: after some further testing the issue actually might be base growth boost of the greenhouse and polytunnel. Expected growth rate is 10% and 20%, but I was only getting 9.1% and 16.6% in my testing. For the polytunnel and greenhouse that had a noticeable knock on effect on the lights and fertilizer growth rate (assuming they are both actually +10%). Weirdly the farmlight and fertilizer values for the greenhouse actually came out higher than expected. Never mind the crossed out part, I'm pretty sure I figured out how the bonuses stack. They're both still coming in lower. :END OF EDIT
I noticed that my watermelon and tomatoes are maturing to a harvestable state later than they potentially should be in greenhouses and polytunnels.
I did some testing and the growth rate outside with no boosts to growth rate and got 10 and 7 days exactly (to the hour and minute of planting) for watermelon and tomatoes, but when I tested them in the greenhouse and polytunnel (with farmlights) they were taking an extra ~50 (Greenhouse) and ~25 (polytunnel) minutes to mature than they should have with 20% and 30% growth rates bonus. I did monitor the crops for the exact (or as exact as you can be with time advancing in 5 min intervals) time they matured and were harvestable and compared it to the expected time based on when I planted them. I only did one set of each.
Not sure if it affects any other plants, I only noticed it because I have a chart of what days to check on which crops in the polytunnel and it is based on 70% of the initial growth period rounded up so all the harvestable plants will be ready to collect at once in the morning. I kept seeing that the watermelon and tomatoes were not ready until later in the day so I decided to test it.


