Serviceberry (Amelanchier) or Hawthorn (Crataegus) would be great. In fact, a mix of the two would be even better.

Not white, but I always think of various Redbud.. Might also consider American Fringe Chionanthus virginicus tree if you have at least moderate drainage. It is native to much of South Arkansas as well.Perhaps some of the larger Virburnium's would work well also. There are native Dogwoods Conus sp. that would do well. You might be happiest mixing a number of species, so that you have a more prolonged period of spring flowering.

Arktrees

This post was edited by arktrees on Mon, Apr 7, 14 at 8:52

the predig thing wasnt great ... but so be it.. now we have to cope with it ... you dug too deep.. and now there is a potential that whatever you plant.. will sink in as it settles.. ending up too deep .... so .. if you happen to have a backhoe.. since i cant believe you dug those holes by hand... you might want to firm up the center of the holes, depending on how big the root mass is ...

do you have any idea how many trees you need for the length given...??? .. what are you thinking along these lines??? ... see link at 5th pic .... that looks about 40 feet wide ... and if you planned to have them never touch.. you would be talking ... about planting them 50 to 60 feet apart ..

one thing for sure.. diversity rules... do not plant more than two of anything ...

however.. until they grow that large.. you could plant smaller trees in between the 50 to 60 feet apart ... and in 20 or 30 years.. when they fail for lack of sun.. so be it ... though the redbud suggestion would work.. as they do fine in full sun.. but are also considered an understory tree ....

are you on a heavy budget and thinking very large transplants??? or smaller.. easier stock??? .. one thing for sure.. you are going to have to figure out how to get water down 400 feet to insure proper watering for up to two years ... and further.. if its not a straight line from the spigot ... and if its uphill.. you better be hoping you have the requisite water pressure .... the larger the transpalnt.. the larger the stressors.. and the more important aftercare is ....

you are on the very edge of proper planting time in AR... if what i glean from other GW AR friends ... timing is very important with planting trees ... i do not suggest planting after 6/15 .. until fall ... and if you cant get it done by then .. you find the fall planting time ... however if you are having this done professionally.. with warranties.. then the window expands .....

i am not familiar enough with AR to make specific suggestions.. but my default is always oak.. for those 100 to 200 year heritage trees ... have you spoken with your county extension office about what local suggestions might be ....

i am sure JonDoe of AR will pipe in ... and i see ark already did ...

my point is.. the selection of trees... is the last consideration ... and perhaps you have already considered the other important aspects.. though you provided no history of such ...

good luck

ken

ps: i do not believe. that trees ever need fertilizer ... especially recent transplant ...

Here is a link that might be useful: 5th pic

stack,
Ken makes an excellent point, and is basically correct on the planting time for far south Arkansas. You either plant NOW, or next November. If now, there will be much care required through the summer, and if now, the planted trees can't be too large. In my part of North Arkansas, Redbuds and Serviceberry are just beginning to flower, I had 24F a few monrings ago, it's BARELY "NOT-WINTER" for me, and so there is time yet. That is not so the far south of the state, you would really be better served at this point to wait until fall. The trees will have time to put down some roots over winter and next spring before summer hits. If you really want to plant now, it can be done, but it will require allot more care.

Arktrees

This post was edited by arktrees on Mon, Apr 7, 14 at 16:57

Mix it up is right. Ask the idiots at the park service who planted that monoculture of ash trees by the gateway arch. Oops a bug which specializes in killing ash came along and is costing us $$$$ and a generation of time to replace.

Idiots.

But anyway, maintaining a true screen is difficult. The lower branches just get shaded out.

Try to squeeze a metasequoia or bald cypress in there if you have enough of a water table. Both grow fast and seem to retain some lower branches naturally.

Thank you for all of the replies. I do realize the holes i pre-dug are deep, but when I backfilled I did pack the topsoil-clay mix tightly in the bottom half of the holes. I believe I will wait until Fall to plant. Would 5'-6' trees planted in October be a good choice for size? Also, the line of trees is at the front of my property which is lower than the center so natural water runoff from rain should help some and I have also made plans to run irigation to the tree line once the trees are planted. Somer on my place is hard on new plantings, the grey gumbo winter clay turns into clay concrete, that even a PTO auger with two grown men as added weight cant cut.

Regarding selection...if you are considering the beautiful Hawthorne suggestion which does very well in clay, make sure you do not have a lot of cedars/junipers nearby. That encourages the spread of "Cedar-Hawthorne Rust" and your Hawthorne's won't flourish. They can be prone to various diseases, so perhaps not the best choice.
The fringe tree is harder to find, but is very disease resistant.

Here is a link that might be useful: cedar-hawthorne rust