Well you didn't say how big they are now, but lately I have been breaking all the rules for spacing shrubs. Like you, I have been grouping similar shrubs together, and I have been putting them close, almost touching, with the plan to move the middle one out when they start to really spread.

I am tired of spacing things with the eye toward mature growth. Following the rules has made my yard look like a plant campground instead of like a garden. I want things touching each other to create masses!

You haven't been gardening long enough gardenscout. It is a real pain to move or remove a mature shrub. It often takes four years or more for some plants to settle in and really take off.

I planted things close for years when I first started gardening but now I don't want to have to move anything anymore or always have to prune it. And nearly everything grows bigger than you think it will.
Once shrubs get big it can be difficult to successfully move them also without major equipment and even then they might not make it.

i have seen one.. at least 6 feet wide.. and 10 feet high ... no clue how it was maintained ... in other words.. i dont know if that was a natural shape tear drop shape .. or pruned shape ....

so 6 foot on center.. may not be far enough.. depending on how much you want to shape it ...

ken

Now I am thinking 8' centers. I appreciate both of your replies!

check out the 1st link... at the link

might want to go even further ....

i guess it all depends on whether you live in a park with lots of space ...

or if you are going to have to prune it into some specific size due to suburbia ...

ken

Here is a link that might be useful: link

I won't need to prune them and I do have enough space, if not a park!
They will back up somewhat to a pine tree grove and will be seen from a front and side view. So they won't get that completely full rounded look as in the link, picture number two. But they will get full sun.

8-10 feet tall by 8-10 feet wide is a good size to project.

At 6 foot centers, they'll certainly touch. 8 foot centers, they'll touch in 8-10 years with very minimal pruning for even form.

I've got 10 year old plants this size. I planted masses more than a dozen years ago that are sheared annually, and these are 8'x8' individually.

Just do your pruning shortly after flowering finishes and new growth extensions begin, and you'll have fine flowering every year.