I understand you are confirming rose identities one at a time. You can update the Plant List in several ways. I'm going to apologize in advance for the length of my explanation. HMF's software is intuitive enough that doing these things takes less time and effort than reading about them.
First, you can use the UPDATE PLANT LIST button that appears on the page of Plants Grown for the Historic Rose Garden. That software helps you search for roses one at a time to add to or delete names from the list.
As an alternative, if you compile a large list of roses, you can upload the entire list using the UPLOAD LIST OF PLANTS button on the same page. This is the software used by HMF admins, by nurseries and by gardens to upload and maintain their own lists of 10, 50, 500 or 1000 roses. If you click the UPLOAD LIST OF PLANTS button, you will see a series of windows, each with a HELP button providing detailed instructions.
As a brief summary... the UPLOAD LIST OF PLANTS software works best with a plain text or spreadsheet list of roses. A list on your computer's Notepad would be fine. I use freeware called TextWrangler which I prefer to TextEdit. Word has extraneous code, but a spreadsheet list is fine. The simpler and better your list, the smoother the upload.
The software uses a two step process. First pass, the software tries to match the names on the list to the names of roses. You then manually check off the right rose from the selections presented. If you are left with unmatched roses, you complete all the steps of processing the list, going through the windows to the end. Those names you successfully matched will be added to the list of Plants Grown. Then you make a second pass using the UPLOAD LIST OF PLANTS button a second time. Menus will prompt you to choose whether you want to upload a new list or to continue processing the first list with its unmatched roses. FYI, unmatched roses usually have spelling inconsistencies, extra or missing spaces in two word names, incompatible symbols or other details that confuse software. Instead of letting the software try to match rose names, you will select "Manual matching." Again, a series of windows with HELP buttons will direct you in matching the remaining names one at a time. As you match each rose, it is removed from the list.
Both methods require attention to detail, primarily because of the appalling reuse of rose names. You will have many choices to make. The larger the list, the more time the automated list upload will save you. We've proven over and over that it saves time compared to the manually updating plant lists one at a time.
A third way to update the plant list is from the GARDENS tab of any specific rose. If there are synonyms for the rose name, be sure that the synonym you prefer is selected, active and displayed in blue bold immediately beneath the tabs. Then select the Gardens tab. You can add the Historic Rose Garden using the MY GARDEN button.
Hope this helps.