Do you think they wouldn't grow on St John?

I haven't seen one here on St. John or on St. Thomas. I would really like to put them on the hillside behind my house as our new home landscape will be more of a Mediterranean look.I am not encouraged by the two nursery's here. As they have to be special ordered shipped and planted I thought someone might have a word of advice.

They grow here in San Antonio, with 28 inches rain/year, and 4-5 months of 90F heat, quite un-Mediterranean. They are very popular in famously Mediterranean 10-inch/year San Diego CA.

Are there USA-to-USVI plant quarantine rules?

You can get 50 seeds for $2.85 here: http://seedrack.com/03.html

I got 2 out of 50 Italian Cypress seeds from seedrack to germinate (out of over 250 seeds I got from them, I had, on average, less than 5% germination). They are about 8 or 10 months old now and about 1/2" tall so I think if you are looking for hedging material you are much better off buying mature plants. But otherwise, I live in sub-tropical zone 10...and they seem to like it just fine.

Yes Italian cypress can grow in the U.S. Virgin Islands. My parents have about five of them growing in their yard in St Thomas