From Hidden Springs, https://www.hiddenspringsflowerfarm.com/

"Thanks for the questions on the new 2018 catalog. Wow I guess people are really waiting for it to be posted. It will be posted as soon as next week. Not everything is offered every year. There are 109 that will not be returning from the 2017 catalog so we encourage you to order those items you would really like to have in your garden when the catalog is posted. If you wait too long some items will sell out before the new year. Most importantly the ones that are listed as LIMITED will not be on the Last Chance Sale and not available in 2019."

You snooze you loose.