Analysis
NAICS 44424 is the 2022 NAICS industry for nursery, garden center, and farm supply retailers, part of 4442 (Lawn and Garden Equipment and Supplies Retailers).
It has only one more detailed code, 444240, which covers exactly the same activities; the definition, index entries and statistics are on that page.
County Business Patterns publishes no national count for it, either because the code is out of the survey's scope or because the figures are suppressed to protect individual businesses.
Official definition
See industry description for 444240.
Source: US Census Bureau, NAICS 2022 Manual.