The leaves of my brugmansia had holes like that, and I sprayed a mixture of molasses, dish soap and water on the back and front of the leaves, and it quickly fixed the problem, which might be very small caterpillars or bugs--you can usually see them if you carefully study the back of the leaf. You can find the ratios on the Internet (for the spray). It also looks like it may be getting too much sun (although it likes sun) and if it's hot, you may need to water every day. Brugmansia also do well with a bit of tomato food--that has made a difference with mine. Good luck.

It looks like it needs some tlc.Don't be afraid to cut it back,it will come back.You can even take a branch plant it and make a second plant,oh and by the way those green worms love them,which is probably where those holes came from..

Yes....cut all the way back..don't overwater...a little liquid fertilizer now and then. You'd be surprised how fast they come back when put outside again and bloom. It looks like it needs cutting back. In summer give it some doses of Bayer systemic fertilizer and insecticide.