it has the potential to be a 60 foot tree...

tree time is counted in decades...

how fast a trees grows.. is a function of the transplanting.. how.. when.. properly.. as well as follow up watering..

if you transplant 6 top 8 footers.. it might be 3 to 5 years.. before they get moving.. because during that time.. they will be growing the root mass requisite to start great growth above ground...

smaller transplants will grow the relative root mass faster.. and in said 5 year period.. probably outgrow the larger transplant..

you seem anxious.. there is no fast remedy to your eavesdropping neighbor in the tree world... the tree will get there.. but do understand it will take years...

if you want this fixed yesterday.. build a pergola.. and add a roof and garden drapes if you want privacy yesterday.. and after that.. then plant the trees.. so that by the time it rots out.. the trees will do the job..

for general info: https://duckduckgo.com/?q=Elaeocarpus+decipiens+annual+growth+rate&t=ftsa&ia=web

i usually refer peeps to local experts.. so i would put heavy stock in the suggestions made [presuming its a high end nursery, which presumably knows what they are talking about] .. but i have to admit.. i know nothing about CA horticulture.. nor plants in your zone... so we will leave that to others...

ken

Oh for heaven's sake!! " but i have to admit.. i know nothing about CA horticulture.. nor plants in your zone... " So why bother making any comments about something you know nothing about?? How is that the slightest bit helpful?

Lots of trees and shrubs have the potential to grow very large in their native environment but will not grow nearly as large in a cultivated or garden setting. This is a very popular hedging plant that is used extensively in climates it is suited to. And 'hedging' implies that pruning may be a qualifying factor. I doubt there are many 60' tall hedges in FL or CA!!

The rate of growth IS moderately slow so I would opt for larger specimens to begin with to achieve the privacy screening you need in a reasonable time period.

This is a tough, adaptable and attractive evergreen shrub with flowers that attract pollinators and fragrant, often colorful foliage. And well suited for your location and growing conditions. And purpose.

@gardengal48 (PNW Z8/9) Excellent! Do you know if they can handle full sun, southern exposure? It gets very hot in the Central Valley and plants tend to fry up here during heat waves.

One of the largest suppliers of these shrubs is located in Texas, Arizona and throughout Southern California, among other locations. If they can withstand Arizona or Texas summers, they should certainly be able to tolerate the Central Valley heat!! They are not overly drought tolerant however, and would appreciate periodic deep watering their first couple of seasons to get well established but require less as they settle in and mature.