Question
Hi CL,

I really enjoy listening to you on WXTK and reading your posts here.  I live in Falmouth and would like to create a 70' "green wall" between me and a neighbor.  The area has partial shade, and I would like these to mature to about 10-12'.  The important things to me are fast growth and low maintenance.
My plan was to buy 3-4' plants and space them ??? apart in alernating rows (like a checkerboard)
The soil is obviously very sandy here, and I would like to get a load of compost? topsoil? to prepare these holes for planting...how big should these holes be? Should I use 100% new material for this or create a mixture of old and new?
I am also curious about watering (we won't be on the cape for another 6 weeks) would daily watering with a soaker hose be adequate?

THANKS for your guidance.

Answer
Chris,
1. Your desire to have both fast growth and low maintenance are a bit at odds with each other - a plant that grows quickly does not STOP growing at 10 to 12', so would need to be trimmed - not only that, but plants grow quickly in all directions so you might need to trip these plants as they grow to keep them more narrow if space is an issue.
2. The only plant that will grow quickly in part shade is the Upright Yew. You can trim it as a formal hedge, or more loosely as a large shrub form.  (And in case anyone in the nursery tries to sell you Leyland Cypress remember the following: they grow 40' and taller, are spindly in shade and get 30' wide. They also suffer from winter damage more often than not.  Arborvitaes need full sun as well. Holly and Rhodys, that do well in shade are slow growing. Hemlocks get Adelgid so need twice yearly spraying.)
3. Distance apart depends on how instantly you want the screen - you can plant upright yews as close as 5' apart for quicker coverage, or as far apart as 10' on center for coverage over 12 years or so.
4. You should spread a load of topsoil mixed with compost over the entire area, and dig it in if possible - only amending the holes leads to reduced root systems and plants that don't do well. The other option is to plant in the native soil (sand) and after planting amend the entire area over the top of the soil with a two inch layer of compost followed by a two inch layer of mulch.  Reapply an inch of compost and two inches of mulch annually to amend from the top down.  
5. Holes should be as deep as the root ball and twice as wide.
6. Not sure what you mean by new material - are you talking about the plants?  If so, where is the "old material coming from?" This is a matter of personal choice - you'll have to decide what you want to look at.
7. Daily watering is too much. Water new plantings every three days for the first month or two, then every five days for the rest of the summer and once a week in the fall.  Next year, once a week from spring through fall.
all the best,
C.L.