It is much easier to just stick a length of cutting in the ground, patchworkfarm. You don't even need rooting hormone.
Get a few 6 - 10" cuttings from someone. Easy does it.

I stuck a bunch of them along the edge of my border once. Man, I swear: every piece of them took roots. I had to remove them all because my front yard turned into a jungle.

Thanks, but I dont have any to start with!

Are they invasive?

I'm looking for a little winter interest in my yard, but if this is a weed shrub, I'll keep looking . . .

It depends on the variety.

Cornus alba does not spread by roots so it behaves very well. The stems that bend and touch the ground do take roots. You might want to keep cutting them off. Old growth needs to be cut off each spring anyway to encourage bright winter color.

Cornus stolonifera and Cornus sanguinea spread by roots. I regret planting them to these days, because I have a very small yard. There is no room for them to spread.

All are beautiful in winter.