Shade Tree

I need shade in my backyard, my neighbor has an ash behind her house that has only been there about seven years and is as tall as her redwood which is the same age. I would like to know pros and cons about this tree. I believe it is a green ash. Thanks

I'm sure there are many who will not like ash, but I love them...grow fast, tough, I think they're graceful. I have quite a few ash. I have quite a few because the Mother Ash is (as in 'Mother'), a female tree and brings LOTS of seedling ash trees, which I don't mind, but most probably would. So, apparently that's why most want the male ash trees and they've been used so much....but I've learned from KaperC who is allergic to them that all of the male ash trees that have been planted are a great problem for those who are allergic.....so......

All Ash trees are highly allergenic. There's a California native Ash called Fraxinus dipetala that is lower on the allergy-causing scale (I think it's a contact allergen?), but it won't grow for me. But if you already have a neighbor with one, it shouldn't be a problem, I guess. I think they are graceful, too.

http://davesgarden.com/guides/pf/go/79798/

http://www.calflora.org/cgi-bin/species_query.cgi?where-taxon=Fraxinus+dipetala

It's hard to find a photo of a fully grown tree.