Depth of fence post for english ivy fence?

Hi, We are looking to put in an English Ivy fence. We are thinking to put green treated 4x4 fence posts in at about every 8 feet and attach powder coated garden wire onto them to grow ivy up for an ivy wall. We are getting 16 foot posts. We live in zone 5. Do you think going 4 feet in depth would be enough for the posts?

Do you think this will hold up well? Thanks!

Depth of fence post for english ivy fence?
According to the USDA plant hardiness chart Zone 5 includes areas in Iowa, Pennsylvania, and Missouri (link below). Minneapolis only requires a minimum 42" frost depth for foundations, according to a quick online check, so you ought to be just fine at 48" if frost-heave problems are what you're trying to eliminate. And structurally, I wouldn't think that going any deeper would help much, though a post run 12' high above grade could present some difficulties---you might want to check with local building officials to see if that's even permitted in your location.



Four ft. is a pretty deep hole. Here's how to use a post-hole digger if you only have a couple to do:



http://www.thisoldhouse.com/toh/video/0,...



After that you might want to consider a power auger. You can rent portable versions or you can have a fence company come out to drill with a truck-mounted version.