If you're talking about the tree and you're growing it outside, as a normal tree, its deciduous. If you have it as a bonsai specimen indoors, it's still deciduous or, at best, semi evergreen (but rarely, more semi deciduous, really) - spray with a pesticide if you think its infested with something that makes webs.

spiders will do it good as it goes and unlike what we all seam to learn about bonzi trees unless there tropical trees they realy like being outside just like there larger brothers and sisters.my friend has over fifty that are flourashing outside and he doesnt even protect there shallow pots .everything from giant redwoods to acers,pines the lot.he will bring them in in the summer for a few days but realy they prefer outside.

There are several varieties of Ulmus parvifolia. The smallest leaved just under 1cm long are not hardy ,need frost protection. The largest leaved have leaves up to 6cms long are hardy up to approx. -10 centigrade. I have kept the larger leaved outdoors for years. but the smallest have been frosted occasionally even when in the plastic tunnel.The middle sized it advisabkle to protect, just in case. The large leaved are truly deciduous. The smallest as used for indoor bonsai are evergreen in so far as they drop leaves as new ones develop, also when moved from hot to cold or cold to hot.