Question
Three years ago I planted three arborvitae within ten feet of each other.

One grew all and busy, one kind of medium and the one is about ?the size of the big one.

They were planted in an area that had a big pine tree that had to be cut down.

Any idea why the difference in size?


Answer
were they all three the same type of Arb? also, sun conditions could play a role. the old tree may have an effect on the growth of the new plants as well. are they on a slope? amount of water could contribute. without knowing the area, it is hard for me to tell. in general, in the same growing conditions, plants of the same exact type should grow about the same. you may be able to have a soil test done to figure things out.

Good luck.

Mark