Need a fast growing and high hedge for zone 5b.

We purchased a new home last year and I got great help from you guys in identifying plants and getting maintenance advice. I'm hoping for some help and advice again.

We had 3 nonflowering pear trees along a back privacy fence that blew over in a storm this past fall. They were 15 years old and beautiful. We were so sad, but thankful nothing was damaged. Now we are left with a dilemma. We have a raised back porch that looks over a 6 ft privacy fence into our neighborhood's "dump". ie; the one house in the 'hood that offends everyone from their burning garbage, broken down vehicles littering the yard, blue tarp across their roof, to going door to door begging for money. We have a half acre, but our yard sits mostly on either side of us and is very narrow at the point of our back porch. We are having the stumps of the 3 pears removed this week and are looking for a fast growing hedge that will reach quite high, but will not take up a ton of yard space. We have maybe 20ft from porch steps to privacy fence.

We are considering the hybrid willow (salix hybrid) From what we read it grows fast, and can handle winds well. Is anyone familiar with this plant or does anyone have any recommendations I could look up?

Thanks in advance!

A really rough guide:
The faster it grows the more weed-like the plant.
It may have invasive roots, hard to garden under or break pipes.
It may have brittle wood, breaks in the wind.
It may reseed rampantly. .

Really look into each plant you consider, using the full botanical name, including variety, and research what these problems might be.

Pay the most attention to research in similar zones. A plant might be a pest under certain climate conditions, and be much better behaved in others.

How tall a plant do you need for privacy? If a plant grows reasonably fast to that height, then slows down that would make a good screen without getting out of hand.
A plant that stays narrow in one direction (won't intrude into your yard too much) also stays narrow the other way, so you may need more of them to grow together and make a screen.

Do you have any more info about the hybrid willow you are thinking about? Does it have a variety name?

Thank you for all your information, Diana. I have tried to research this tree as much as possible with my basic knowledge of plants. We first saw the salix hybrid in a mail catalog and then I began to look up more information. It is my understanding that it grows quite fast in the first few years if given the right maintenance and then it slows down a bit. It can be trimmed and trained. It does not reseed or have root suckers. Here is a link from one online company selling them and their description.
http://www.advancedtree.com/Tree-Skyrise.aspx

I see conflicting information at that site. One line says to plant them as close as 5' apart, and another line says they can get 20' wide. Nearer the bottom it says 40' wide.
The pictures all confirm the very large size.

If plant can be kept to 1/4 of their ultimate width, it is only with consistent trimming. As fast as this is said to grow that is going to be a LOT of trimming, several times per year.

Take a tape measure out there to the narrowest part of the problem area, and see how much space you are willing to give up. If the area is only 20' wide, and the bush grows 20' diameter, then half your space is gone. If you are willing to trim up the lower branches and grow it as a tree, it is OK if it overhangs your house? 40' diameter is a wide spread. The area under it will be dense shade.

The article specifies that the roots can be 10' or more outside the drip line (outline) of the tree. So, tree grows 20' radius, roots will be 30' radius. Even if you keep the top (leaves and stems) trimmed back as a shrub, the roots will still try to grow out that far.

Not to be a Debbie Downer...but my personal experience with Salix is that they tend to be fast-growing and brittle, prone to storm breakage. We've grown (and lost to storms) corkscrew willows and right now our property has three plain willow trees - not planted by us. Willows are also very thirsty plants - that can be good or bad, depending on where they are planted.

I'm not sure what choices will do well in your specific location (you're considerably colder than me), but if your space is narrow, I'd look for plants characterized as "columnar" or "upright" as they will be the most likely to stay in bounds with minimal pruning.