Wet: some edge plants lead to over-watering problems, making the facility very wet for a while. During this period you can find units of Clay (raw material).
Dry: some edge plants dry out the facility, making its surface very dry for a while. During this period you can find units of White Sand (raw material).
Stony: some edge plants foster the rising of stones, making the facility very stony for a while. During this period you can find units of Rock (raw material).