This is what they looked like a month ago when I installed them. Watering 3-4x per week except when it rains, about 10-20 minutes per tree with a sprinkler. The brown came on very quickly like a week and half ago and the leaves are falling off too.

Hi David Caglia, good news for you, your leyland cypress is as dead as a doornail. This gives you a chance to plant something else, something different. A search on diseases of LC yields countless results. They really should be taken off the market.

Not surre about your magnolias, I'm in MD and we have had abundant rainfall. Arre they wobbly

and come loose easily? Check and see if the roots are brown & rotted.

Not a tree expert, but, when we got our magnolias and dogwoods, my farmer father in law was adamant about distance between trees. Could they have been planted too close together for more mature trees? (we also planted ours when they were half the size of yours).

Those are all planted too close together, but that's beside the point. Leylandi are awful as indicated above. Excess water should not generally bother magnolias. Here's how to water newly planted trees and shrubs for the first 2 years they are in the ground. Monitor how much rain you get per week. If you do not get the equivalent of at least 1" of rain in a week, then you must water your trees and shrubs. NO SPRINKLERS. Get a "bubbler" attachment for your garden hose, or just put the hose on a very slow trickle and leave it on each tree for a good amount of time - with a bubbler, at least a 1/2 hour. With a trickle, at least an hour or more. If it is particularly hot (90s etc), consider supplemental watering.

Another thing, were they balled and burlaped and in cages? All that crap needs to be removed when you plant.

And here with a dissenting viewpoint, if you are attempting to create a dense Leyland cypress hedge, they are not planted too close together. 3-6' is the recommended spacing for a dense, screening hedge.

And depending on location, Leyland cypress are not the "awful" plants others make them out to be. Here in the PNW, they are seldom ever bothered by any disease or pest issues and there are gorgeous mature stands of Leylands to be found all over the place. If anything, root issues from too confined container growing practices can be a problem but even that can be adjusted or compensated for.

FWIW, at my previous residence there was a 20 y.o. hedge of Leylands separating my neighbor's property (planted by him) from mine. These were planted 3' on center and received an annual side shearing to keep the width in check. Periodically - not not every year - they would be topped for the first couple of feet to also keep height in check.

Yes: if to be used as a small religiously sheared hedge - which is actually feasible with Leyland - the same close spacing as is used with other kinds of plants being employed as sheared hedge material works. However the specimens asked about on this thread are already bigger than one would start out with to produce this effect.

And are farther apart.

It is not at all uncommon to see Leylands planted here with that spacing that are left unsheared. I can think of several local plantings with similar spacing that accommodate pretty large trees...easily 30' tall, sometimes more. A very popular screening plant for uses where space is not at a premium.

If you are trying to argue with something I posted I have no idea what that is.

I had several large evergreens planted a few years ago. It was recommended that I purchase tree ring tube watering devices for them. You wrap the inner tube like contraption around the tree trunk and then fill it with water. (They do come in different sizes.). It slowly releases the water. When the inner tube is empty, you refill it. I did this every day for most of a hot dry summer. All of my trees survived and are thriving. It was worth the investment!