Pay ‘em alittle more. They are out there
Actually, I think there is reasonably simple solution. The cost of an H1-B visa is 1 million dollars apiece, you may buy as many as you want. An exception is made for agricultural workers.
If the tech industries are so starved let them fund the universities and colleges to teach to their needs. Alternatively, and I think this is a much better idea; let the tech industry found their own schools to teach the skills they need.