Currently we use Hawtio (JBOSS) to manually test FTP, can this be automated using SoapUI

Yes, this would be quite straight forward.

1) Identify a suitable Java FTP library, such Apache Common's FTPClient.

2) Add this to the SOAPUI java.library.path, which can be found using the following Groovy snippet

log.info System.properties["java.library.path"]

3) Create a Project with a Groovy Test Step

4) Code a little Groovy to perform the FTP operation you want. e.g.

import org.apache.commons.net.ftp.FTPClient

new FTPClient().with {
    connect "ftp.example.com"
    enterLocalPassiveMode()
    login "username", "password"
    changeWorkingDirectory "/blah"
    def incomingFile = new File("local-filename")
    incomingFile.withOutputStream { ostream -> retrieveFile "remote-filename", ostream }
    disconnect()
}