agla:
The winters here are wet in a normal year. In the Willamette Valley, we should average about 37 inchs of rain a year between mid Ocotber and mid May.
The majority of the soils where the trees are grown is on deep, modified alluvial plain soils washed down here in the Missoula floods.The entire Willameet Valley has these or some modified types of these soils in over several million acres. A nice rich mixture of sandy loam, clay, that when properly watered or with natural mostiure has excellent holding capbilities when dug anywhere from 28 inch to 96 inch size in wire baskets.
The majority of the digging is done starting about Feb 1 to June 1. The nurseries will supplement water the trees to be dug if the growers feel the mostiure is not sufficent at digging time.
These soils are so deep in some spots, that there is over 22 feet of top soil. A good friend owns one of the largest tree nurseries in the Northwest and they have been growing and digging trees on 450 acres for over 25 years now.
We have 3 soil classes on 5 acres at our place. We are in "bottom ground " which a portion of it floods every year. We have aproximately 1.5 acres of container yard and greenhouses, 1.5 acres of stock growing ground, and another 1.5 acres that we are growing rushes, sedges and native grasses for division and seed on. This portion flood every year, but it does not affect that type of plant materials.
We fallow out portions, and let the native grasses grow back and just let them die off and re seed. We had all 3.5 acres in a crop conservation program and let it grow for 6 years with out mowing, cultivation. We added over 3 tons per acre organic matter back to the soil profile and it became better soil than it every was before.
We DO NOT dig and sell anything balled and burlaed, or with native soil on it. Every thing is containerized for finishing, native soils are used for propagation only.
In this case of tree planting, we would provide follow up care under a maintenance contract, for just the tree if nescesaery, documenting everything we did or they did. No contract, no guarantee, you must sign off on it.
I would not dig the tree out of the afore mentioned time window. We did move some lindens in 60 inch root balls in early March, 25 of them, I had a spade truck come in, cost me $ 350 each to move them 20 feet each, 100% survival. Our rain is well below average this year, about 7 inches under normal.
We planted 12 western red cedars, 15 feet tall last week and we augered up almost dry soil. The trees were well watered before digging, we watered them in and I don't see any problems.
We have 103 shade trees going in next week, and will use the same process there as well.
Check out this nursery, it's owned by a life long friend, and adjacent to our property.
http://www.efnursery.com