Find out the mature width of the tree (one site says 'Forest Pansy' has a mature spread of 25-35 feet wide) and divide by 2 (since width is the total of both sides). That means you probably don't want to plant anything closer than 15 feet to the trunk of this tree. But of course the other tree has a width too. Assuming you are getting Cornus florida, the mature width appears to be 15-20 feet. So allow for 10 feet on each side. So now add that 10 feet to the 15 of the other and you want these planted about 25 feet apart. Make sense? You can be more or less generous as you see fit.

I have 'Forest Pansy' - the color does mellow a bit over the season; if it gets enough sun, it should retain a soft purplish cast (too little sun and it reverts to green). Definitely not as deep as purple plum.

Hope that helps.

Planting distance for long term development is the same as estimated crown spread - no need to make it more complicated. If they all grow 30' wide, plant them 30' apart. One grows 20' wide, another 15' - picture each as a circle that wide on a piece of paper and space accordingly.

That's if you are planting a sort of border of shrubby trees. Tree-like specimens with elevated crowns register as accent points in the landscape and should be widely spaced as otherwise a cluttered effect may result.

When all the trees are the same kind they can be grouped closely together to form a grove or clump.

'Forest Pansy' does fade in hot weather, so that you end up with only the newest leaves being purple later in the season. One on a Seattle (USDA 8) street had an average crown spread of more than 30' some years ago.

Native pretty consistently to hot summer climates only, redbuds need a warm situation with good drainage; many plantings have problems with dieback if not well sited.

Depends on the look you're going for.

I have regular redbuds and dogwoods in all kinds of random places in my yard. They're not huge trees, really understory trees in the forest. I saw some of both hiking today. Popping up along the edges of a trail. Sometimes a little "crowding" can produce neatly shaped trees.

Another color to consider adding to the mix is from "Appalachian Red" Redbuds. Quite different, a neon majenta is how I'd describe it.

Thanks all. I think I will need to pace it out. Should I go for 2 dogwood, I could probably space them a little closer together.

The biggest issue may be finding the space due to competition from exising roots. I have removed 2 large junipers, and a pine tree, but there are existng roots from those as well as other trees. I can raise the bed there a little. Any suggestions on what tools to use to remove roots that are no longer connected to anything?

IF you're sure there is nothing underground to cut I've done wonders removing honeysuckle roots with a sawzall. Not as fast as real heavy equipment but a reasonable price and great for other cutting tasks too.

When I've cut down ash and maple trees that don't re-sprout I just leave the roots in the ground and let nature take it's course. I figure there are plenty of dead roots decomposing under other trees in the forest so it's all part of nature if ya can get your new plants in around them.

Another redbud cultivar to look into is Little woody. It is smaller and with a very nice leaf.

As far as removing roots I used a Mattocks.

David