leyland cypress
the way my yard slopse the only way i knew to create some privacy was to plant 32 leyland cypress trees around the perimeter of my back yard, luckily my neighbor to back has some and neighbor next door has a row too. i've heard good and bad but they grow fast and can add some cheap screening but as most are doing great 3-4 have turned brown and i don't know if its because they sit in a wet area or they aren't taking as these aren't growing either. in spring i may pull them and replace them with some 3 gallon starters .
My book says they grow quickly but advises you only plant small ones, no more than 3 feet tall. Trees often take a year to establish themselves when newly planted, putting on growth from year 2 onwards. It also suggests an alternative for moist soil - Chamaecyparis lawsona 'Alluminii'.
I, too, planted a bunch behind my house, basically to block out the neighbors directly behind us. They started off slowly, but after about the third year, they went CRAZY...they grow about 2 feet every year, and that's in really lousy clay and shale! I highly recommend them...they are BEAUTIFUL too! Be sure and leave enough circumference for the growth potential. GOOD LUCK!
wholenote i agree i planted some at a angle to second drive way 20 years ago and they are at least 15 feet tall, i've yet to figure out why i didn't do the back yard perimeter . yes in Georgia we have that crappy red clay but it doesn't stop them from growing as thats why i chose them, i just wish the few would follow their brothers and grow. i always hear pro and con to growing them but i'm not deterred.
i have about 10 i planted about 20 years ago at the side of my driveway and are at least 15 feet high and i don't mess with cutting or trimming them. i planted them about 6 feet apart and they were the gallon size one which cost about $5. a piece the larger 3 gallon cost about $8. at discount nurseries . all my neighbors have them and haven't seen one tip over yet and yes other than the few i have in wet areas they grow fast ,planted 32 around perimeter of backyard and i think this is third season and most are at least 5 feet tall. you do need to check what zones they do good in as i'm not sure of that.
looks can be decieving i went out back the other day and was walking the perimeter of my backyard and standing beside the leyland cypress and several were as high as 8 feet, i can now see that they prefer a dryer soil over a wet soil as the 4 that stand in the wet soil looks as if they haven't grown at all.
Laylandii have quite a stigma attached to them in the UK. This from wikipedia "In 2005 in the United Kingdom, an estimated 17,000 people were at loggerheads over high hedges, which led to violence and in at least one case murder, when in 2001, retired Environment Agency officer Llandis Burdon, 57, was shot dead after an alleged dispute over a leylandii hedge in Talybont-on-Usk, Powys"
They can be a real pain. I used to dread having to trim the ones in our garden in the UK. I'm told they can also be problematic as the dead foliage that accumulates around them can poison surrounding soil due to high acidity.
That said - You mention that some are browning and appear not to be doing well. In my experience laylandii will grow in almost any soil type so I'm not sure wet soil is the problem. Other reasons for this can include : Saplings being handled badly by nurseries. It's possible these plants were already dying before you bought and planted them. If they've been carelessly transplanted/potted on by the nursery or suffered root damage when planted out they will suffer. It can take a while before you start to see problems as they take some time to brown and die completely - great for nurseries as they look healthy but not so good for customers trying to pick good specimens. I've also found that if they're kept in pots for too long and allowed to dry out completely they will die. Even if you re-begin a watering regime it's likely the damage is already done. They rarely recover.
You might want to pull out the ones that appear to be suffering and replace them with some from a reputable nursery. Steer clear of any that seem to be newly transplanted or recently potted up for sale. They may already be dying. Any that appear to be slightly pot bound (signs of healthy roots growing through the base of the pot) are likely to have properly established in the pot and be more able to cope with planting out. Choose these.
Good luck - I know it will take longer to produce a good screen but you might want to look at other hedge habit species native to your area. They'll provide much better habitat for wildlife too.
thats a good idea maybe i can divert some of the water around these few trees and raise them alittle only talking about 3-4 trees the others are doing good some beyond good. yes i think they will need to be replaced to and i'm thinking of going with the three gallon established ones over the gallon ones and see how they do. a couple loads of dirt may help. my neighbor behind has used railroad ties on her side maybe for the same reason so i may check into that also.