The zone facility in this plant database is the one area where I think there could be improvement. If I search for plants in my zone, it doesn't include plants with a lower zone listed. For example, if I search for:
shrub
perennial
full sun to part shade
showy
pink
8b
I only get 30 plants that have 8b as the minimum hardiness. I don't get any plants with a lower zone as the minimum hardiness.
If I change 1 thing, 8b to 7a, there are 122 *different* plants, none of them are the same. The 8b results should include any plants hardy in that zone but one can only find plants at the very edge of hardiness.
The searches to compare, 8b:
https://garden.org/plants/sear...
7a:
https://garden.org/plants/sear...
I wish there were checkboxes for each zone and when one searched their zone the results included all plants hardy in that zone, not just those that top-out at that zone. Edge of hardiness plants aren't the most reliable.