Tree for alley?
We have a small plot of land outside our fence on the alley where three intertwined trees grew. Sadly, we lost two of the elms to Dutch Elm (and removed the Tree of Heaven at the same time). The trees had a nice, arching quality to them, which we miss. We would like to replace them with one good tree that will grow tall. The area gets a mixture of sun and shade (though most of the shade comes from a neighbor's elm, which looks like it will be next to go). Any thoughts on a good replacement? It should be a fairly tough tree for alley conditions (watering it will be a challenge, though I will try one of those tree bags). Also, when would be a good time to plant?
Thanks for any suggestions.