Hello! My Cornus florida dogwoods are winners. Flowers, long lasting fall colors. There is wild strawberry or yuccas growing under the three established ones I have.

New transplants I would probably just mulch. I have heard they are a bit picky with water requirements so perhaps competition is not the best thing.

BTW, How large were your transplants? Burlap or potted?

While they are getting started I would not worry about using anything but mulch under them and making sure they are adequately watered.

They were small, pot grown and root pruned. They grew about a foot last year, so are now around 4 feet. We had a nice season last year with ample rain, so they established easily. They're not new transplants anymore, but still small. Agree, water and mulch and the primary needs.

As an aside, they are 'Appalachian Spring'. When I ordered them, I expected they would have been cutting propagated, but I noticed when I received them that they had been grafted. I wonder if grafted trees are more prone to fail as they age? Is this becoming the preferred method of propagation for dogwoods?

"Budding" is the propagation technique used to propagate most Cornus florida cultivars, see link.

Here is a link that might be useful: NCSU Budding Site