Hi Dorry, looks like you've undertaken quite a project. I can't help you but call Alan Summers at Carroll Gardens. Steve in Baltimore County

Oscar is right, that's a huge project. Trees that size must have a large root ball taken with them in order to survive. This is definitely work for a professional with lots of manpower and the proper equipment.

Fall is a good time to do it since they have time to settle in before you get another hot and dry summer. But remember that we can have very dry weather in winter, too. Watering for at least the first year is critical if the soil dries out. On the other hand, over watering can kill them, too. A good layer of mulch, properly applied, is helpful to prevent loss of moisture and keep the soil from a freezing/thawing cycle that can damage roots.

If you're using a reputable landscaper who knows what he's doing, you should have good success if the follow up care is done.