I enclosed several images of my tree screening project in Alabama Zone 8. Using excerpts from various threads about these types I finally have my recipe for them nailed down. The trees have been in the ground anywhere from 1 to 3 years in red clay soil. I have the front East line planted with Green Giants and the back line and West side line with Leyland Cypress.

After losing 4 GG the 1st year I had to devise why and what to do next. Long story short I applied my 30 years of earthmoving experience to the solution. Red clay when compacted is very impervious and hard as a rock. The drainage was part of the culprit and the hole width was partial blame as well.

I decided when planting the 2nd line of LC and replacing the GG's. I was going to install 3' deep sumps dead center in the planting holes and fill them to the bottom of the planting hole with small river rock you can buy at Lowes or HD. I mixed Milorganite and slow release fruit tree fertilizer in the backfill dirt leaving the root ball 2" above grade.

I dug the holes twice or more wide and added 3" of mulch staying away from the tree trunks. This seemed to be the ticket for my soil type as you can see in the pictures, they love it and no lost trees to report.

This Spring I took a small tiller and went around each tree outside the drip line and broke up the soil about 3-4" deep. I added more Milorganite and drove 12" long rebar sized holes outside the dripline all the way around the trees and filled the holes with fruit tree slow release fertilizer formulated from the Wildlife Management Group that grows all types of trees. I mulched the whole area I tilled as well. I use no drip line as the Spring has been generous with rain. The trees are reacting like never before after this technique. Granted year 3 "they grow" saying but, year 2 for some of these and their taking off like a wildman! Geat.

I have 1 wild cedar among them and it's growing like a weed as well. You can see it in 1 of the line shots. Morale of the story here is:

You may have to test different theories on what works best for your region's weather and soil types. What works for one person on here may not work for your scenario. Trial and error.

Good luck and I'll post later this Fall on how much growth was achieved this year.

Thanks so much.