Note: The following is a list of trees that can spawn a Thunderstruck with their phase times and chance at each phase. These are exact figures and not compiled from empirical data. Please don't ask where they came from (I'd prefer this thread not be deleted).
If a tree is not listed, it most likely has a very small TS probability (0.01%-ish) for its first 3 growth phase transitions (experimental data suggests 1 out of 1000 for Aspen).
Between each growth phase, there is a half-second transitional phase. AFAIK, the RNG roll happens between the end of the growth phase and the beginning of the transitional phase.
The times shown are from phase to phase. Not total elapsed time.
Tree sizes are shown next to tree names.
Times listed should be for off-climate growth. In-climate growth should be 70% of the listed durations.
Poplar (4.5x4.5)
Small Sapling to Sapling: 1h 12m
Chance for Thunderstruck: 0.01%
Sapling to Small Tree: 4h 48m
Chance for Thunderstruck: 0.02%
Small Tree to Tree: 6h 00m
Chance for Thunderstruck: 0.03%
Rubber (4.5x4.5)
Small Sapling to Sapling: 1h 8m 36s
Chance for Thunderstruck: 0.01%
Sapling to Small Tree: 4h 34m 24s
Chance for Thunderstruck: 0.02%
Small Tree to Tree: 5h 43m
Chance for Thunderstruck: 0.03%
Traveler's Tree (4.5x4.5)
Small Sapling to Sapling: 1h 25m 48s
Chance for Thunderstruck: 0.01%
Sapling to Small Tree: 5h 43m 12s
Chance for Thunderstruck: 0.02%
Small Tree to Tree: 7h 09m
Chance for Thunderstruck: 0.04%
Cedar (4.5x4.5)
Small Sapling to Sapling: 2h 34m 18s
Chance for Thunderstruck: 0.03%
Sapling to Small Tree: 10h 17m 12s
Chance for Thunderstruck: 0.05%
Small Tree to Tree: 12h 51m 30s
Chance for Thunderstruck: 0.08%
Rumbling Archeum Tree (4.8x4.8)
Extra Phase: 10m
Small Sapling to Tree: 50m
Chance for Thunderstruck: 10.00%
Ginkgo (6x6)
Small Sapling to Sapling: 1h 8m 34s
Chance for Thunderstruck: 0.02%
Sapling to Small Tree: 4h 34m 17s
Chance for Thunderstruck: 0.03%
Small Tree to Tree: 5h 42m 51s
Chance for Thunderstruck: 0.05%
Beech (6x6)
Small Sapling to Sapling: 1h 25m 42s
Chance for Thunderstruck: 0.05%
Sapling to Small Tree: 5h 42m 51s
Chance for Thunderstruck: 0.08%
Small Tree to Tree: 7h 08m 34s
Chance for Thunderstruck: 0.13%
Extra phase: 1d 10h 17m 8s
Pine (6x6)
Small Sapling to Sapling: 6h 51m 30s
Chance for Thunderstruck: 0.09%
Sapling to Small Tree: 1d 3h 26m
Chance for Thunderstruck: 0.14%
Small Tree to Tree: 1d 10h 17m 30s
Chance for Thunderstruck: 0.23%
Cherry (7.5x7.5)
Small Sapling to Sapling: 1h 25m 42s
Chance for Thunderstruck: 0.04%
Sapling to Small Tree: 5h 42m 51s
Chance for Thunderstruck: 0.07%
Small Tree to Tree: 7h 08m 34s
Chance for Thunderstruck: 0.11%
Extra Phase: 1d 10h 17m 8s
Ebony (7.5x7.5)
Small Sapling to Sapling: 5h 8m 36s
Chance for Thunderstruck: 0.07%
Sapling to Small Tree: 20h 34m 24s
Chance for Thunderstruck: 0.11%
Small Tree to Tree: 1d 1h 43m
Chance for Thunderstruck: 0.18%