Hello there.  Please send some photos! How large were the trees you had cut back and how old are they?  What percentage of the total size of the trees did you have removed? It sounds like the trees are trying to create the hedge you were envisioning so I am not getting the full picture the scope of the problem. Some  photos would give me a better idea of the issue.

The Laurels were grown as trees before I bought the house. I don't know the age. They were very tall, maybe 15 ft? I had them cut to 10 feet, I'm guessing. They haven't grown much taller but have definitely filled out. It is the roots extending out a foot or more that are producing "new plants". See pics. 

Hello again.  Thanks for the photos!  Unfortunately, there is no easy fix to this issue.  Laurels are extremely hardy and resilient plants.  They can establish themselves here in the Pacific Northwest outside our gardens, making them invasive.  The hard pruning you did to your laurels is exactly what has triggered these suckers from growing up from the roots.  Your desire for a fuller hedge will happen, now you must figure out how to prevent growth where you do not want it.  In the future prune smaller amounts off your plants in one session.  The rule of thumb is not remove more than 1/3 of a canopy at any one time.  A yearly pruning to remove that year’s growth should suffice.  Suckers coming from roots should be removed as soon as they are noticed.  To do this you should tear them away opposite from the way they are growing to remove as much living material as you can get. (hint pliers work great) I do this with some of my fruit trees.  Now after almost 10 years we have finally slowed down the regrowth of the suckers to a point that this is not an onerous task that must be performed several times a year.  You can also prune suckers off as closely to the root as possible but tearing them off is more effective. 

The more difficult way to do it is to dig down and remove that part of the root from the parent shrub that is producing the suckers.  You must be careful and not remove too much of the root system from any one shrub.  If you have large roots this may be a lot more trouble than is sounds.  The final way to stop suckers is to sever the connection to the parent (with shovel or if needed a chainsaw) and to chemically treat the suckers to kill them.  Don’t skip the part of severing the connection to the parent plant as the herbicide can impact it.  I am still trying to nurse one of my small landscape trees back to its former glory after I failed to do this.  That tree has been in decline now for over 5 years.  It has not died but also has not grown much, and I must remove parts of it every year that have died.

Debbie, 
Thanks for the full response and multiple options. They aren't really value added in my yard on that side of the house. Maybe I will have them removed  . . . even though I may have regrowth. If I do have regrowth it will be easier to eliminate with herbicide. What type of herbicide do you recommend? This side yard has no other wanted plants. 

Thanks
Karen

Karen,

Master Gardeners are not really supposed to recommend a certain herbicide. I did find this response from a faculty member: There are also products for killing remaining roots of laurels and several methods of application. Look for “stump killers” containing glyphosate or triclopyr at your local nursery. To be effective, they should be applied right after the tree has been cut down. Read and follow all label directions and cautions.