hi first... all 'ever'greens .. lose their leaves ... eventually ... usually within about 1 to 3 years ..... this is sped up by potting [the wholesaler???] ... moving it from one location to another [greenhouse to seller in big truck ... to roof ... e.g., etc] .. these changes affect its CULTURE ... humidity .. sun ... wind.. etc [just like you moving to from the equator to the north pole.. you will live.. but you will be in culture shock] second... a bad cold winter [did you tell us where you are???] .. in a pot doesnt help either ... especially on a roof ... as winter sun.. warming the pot can be problematic .... etc ... [note all the etc's ... there is just so much going on its hard to ID any specific reason] ... so by the time it gets to this point.. i would just about rule out disease ... mostly because you are supposed to be buying 'clean' stock ... and disease.. on otherwise unstressed plants.. is just not that relatively common ... so i default to bad winter .... so... all that said .. third.. its probably winter damage.. on an otherwise stressed plant ... life is all in the buds.. and i have had alleged evergreen lose every single leaf/needle.. and just bud out in spring.. like there is no tomorrow ... and all you can and should do.. is give it time .... i am of the thinking.. that we dont fertilize stressed plants.. lets just perfect proper watering .. which usually isnt all that much in spring.. with cool nights .. protect it from any late frost or freezes.. especially once it starts budding out ... and .. carp.. coffee buzz.. lol .. lost track ... oh ... and another thing.. lol ... it is your responsibility to train a plant to a trellis.. no plant.. does it itself... ever ... but that is for a later time ... lets get it growing.. and then.. with some better pix.. we can give you some ideas for training it.. into the shape you want ... and yes. we dont cut all the low long stuff off ... some we do.. and others.. we allow to elongate.. so we can bend them back to the trellis for training .... sorta like growing out your bangs ... all that.. or its dead.. lol ... trust me.. we all killed things on the learning curve.. its how we learn .... so give it a few weeks ... or a month.. and report back ... this is not a foo foo plant.. i have high hopes.. as long as you dont kill it with too much love .... ken

Maybe they will hang on by a thread. All you can do is wait and see.

I grow these in fairly dense shade, on the north side of a row of tall blue spruces. They do really well, grow quickly, and can be kept any shape you like - mine are in a fairly narrow bed between a path/pool and the spruces, and I need to keep them narrow because I have smaller plants in front. Mine are on a simple wire fence that gives them support for the first 4 feet - they thread thru the spruces above that, and I see sections up at least 12 feet. If you trim them to 6 or 7 feet, of course they will be bushier. This is an excellent, underused plant for screening. Interesting when in bloom, too - very sweet little white flowers cover the plants.

There is always hope if the plant is still alive! Plants like the euonymus growing in containers will need attention a little more frequently than every 5 years :-) While this is not exactly an ideal time to do so, you definitely need to repot. And I'd do some root pruning as well - shave about 1/2-1 " of the rootball off all around and even bit more from the base. Need a good sharp knife or saw for this. Then repot with fresh potting soil (a good quality mix - not Miracle Gro). Add some controlled release fertilizer like Osmocote and water well. You don't really need a larger container necessarily, but it will extend the period slightly before you need to do this again. Plan on doing this about every three years, maybe every second year if staying with same size container.