My husband and I changed the soil in our crotons and now both plants are drooping significantly and leaves are falling. We've had these plants for over 20 years and I think we've killed them. What can we do to revive them.

They aren't dead, just probably recovering from transplant shock. How did you do it? Did you wash the roots? Leave soil on the root ball?

We removed all of the old dirt and washed the roots, then replanted in new dirt mixture.

You have most likely shocked and damaged the root system. I know its a popular thing that people do, removing all the old soil and washing roots, but its the wrong thing to do. Roots have fine hairs (like capillaries in human circulatory systems) that can be easily damaged by doing that. Its always best to just gently shake off whatever old potting mix will easily fall off, then repot into fresh soil. Your plants may recover, but it may take a while. Or, they may not.

Thanks so much for your help and feedback. I am going to keep the faith and hope that they recovers. We've had them for over 20 years and they weee doing so well. The next time I'll do my homework before I make any changes. I have a few more that were never doing really well Rattle Snake and a version of a monstera that I am not sure about either. The rattle snake has burnt ends constantly and the other one holds water and end up root rot.

That is an Alocasia 'Poly' not a monstera. They like humidity and light. They also have a tendency to go dormant in the winter if they don't get what they want.

You Calathea also needs a lot more humidity

As insurance against losing the vintage crotons, I would encourage you to take a couple of tip cuttings from both plants, take off the bottom leaves and put in water for the winter. If they rehydrate they will probably be fine and well rooted by winter's end. They can then be potted in spring. If leaves look normal after 3 or 4 days and not droopy, they are rehydrated.
Russ
Central Florida

Good to see you on the page again Bluesea

Thanks so much for the advice.