I believe it is in the Spring, but it is not marked on my calender. I just watch for the bloated females and their egg sacks to start appearing, then out comes the raid can for a good coverage of the outside of the house. Mostly they like to nest under our car port and garage area because it is out of the rain.
I give the whole sealing and area a good blast with the Raid spider formula (very good stuff), then leave for about 10 mins. When I come back there are a 100 or so dead spiders hanging from their threads that tried to leave, but never made it out. In a day or so I notice that all the rest have set up shop on our outer metal fence and bushes, which I am fine with. I hope it helps discourages people from trying to climb our fence.
We have a couple palm trees in our yard with a lot of bugs in the leaves. The spiders seem to like those more than anywhere else around our house.



