#1 - yes - they grow in the summer - think of the monsoonal rains in the Sonoran Desert.

#2 - nothing - the woodpeckers won't kill it.

You are growing it in an environment where you'll have to water it more to emulate nature. I'd suggest contacting the Tuscon C&S Club (they do a lot of rescues) to get further information. I myself grew a Carnegia gigantea but they don't like San Diego - it's too unnatural for them.

I would NOT water it!

There was an article about transplanted saguaros in the CSSA Journal a few years back. Let the plant alone, let it adjust to its new home. It's a cactus and can go months without water. Water it now and you could harm it.

Yes there are monsoonal rains, but I used to live in Vegas, and you'd be surprised how localized they can be. One block gets a downpour and the other side of town sees nothing.

Leave it be and let nature water it.

Several decades ago, 1966 or there about, I took an adult extension course at the Desert Botanical Gardens in Phoenix. The instructor said to watch the news and water one's cactus whenever it rained it Tucson.

As someone noted above try the Tucson Cactus Club. I would not get too excited about water or not water just now. A five foot saguaro should be able to survive either for a season or two.

I would NOT water it!

There was an article about transplanted saguaros in the CSSA Journal a few years back. Let the plant alone, let it adjust to its new home. It's a cactus and can go months without water. Water it now and you could harm it.

Yes there are monsoonal rains, but I used to live in Vegas, and you'd be surprised how localized they can be. One block gets a downpour and the other side of town sees nothing.

Leave it be and let nature water it.