searched the whole web.. eh??? after ten years.. my GG is 20 feet tall ... from a 4 incher planted ... after ten years.. my smargard.. emerald green ... is 6 feet tall from a 4 footer planted ... try googling green giant for it latin name ... and then add: annual growth rate... and then google for emerald green latin.. and add the same.. and you should find.. one grows 2 to 5 feet per year.. and the other 6 inches or so ..... depending on your climate.. you better have a pretty big yard for GG's ... and on either.. INSURE you buy single leader plants ... welcome to GW.. glad to help .. come back often .... ken ps: the latin names are VERY IMPORTANT.. its where you start all searching .... trust me.. i fought them for years.. lol ...

This is a great thread. I am new to this, but finally got my back patio looking great after living in my house for 14 years. I decide to enjoy my new fire pit and realized THIS is my current view. It's probably pretty obvious why I planted these trees, not to mention the loud kids running around in the back yard all day. But after reading a LOT more about these monster trees, I feel like I may have overshot the runway? I planted these 6' off the property line (and 6' apart, not to their trunk center but the edge of the hole...oops) but am still afraid they may grow over the neighbor's yard. There is no fence or other obstruction between our yards (well, except for the, you know.....Dodge Durango!?!) so I am a little concerned about the intrusion in to the neighbor's property. We aren't the best of friends either, so there's that. The trees are about 18" now so won't be an issue for a while, but they are still young enough I could replant if necessary. I included two pictures to show the property line and how much of my yard space I'm giving up (which I am HAPPY to do to eliminate that horrible eye sore!) Any advice on if I allowed enough room for these things?

Did you ever get it figured?

" an(y) case studies that could be referenced. " Not really :-) Growing habits and mature size are highly influenced by location, soil conditions, aftercare and weather. Generally, correct spacing for a plant is at least half the distance of its mature spread (12' spread = 6' /20' spread = 10') but for a solid hedge, you can space closer. There IS a point that is too close but common sense usually prevails. I would not site anything closer than 4' for a solid hedge. Spacing of a staggered double row of GG's can also be slightly closer.....5-6' on the diagonal. My personal choice is to space them a little more generously for all applications but then GG"s grow fast and big here.