Something i've been working on is the predictions on GrowStuff.org. If you go to you gardens page there's now a progress bar for each annual planting. That's plantings that are expected to complete there lifespan in 2 years or less . the progress bar is % until the plant is finished and can be removed.
I also built a "first and last harvest" predictor. It's based on the median time from planting a plant until it is first harvested. It's only as good as the data on Growstuff.
Right now, coriander says: Median lifespan of coriander plants is 156 days. First harvest expected 36 days after planting. The last harvest expected 115 days after planting.
Meanwhile, basil says: Median lifespan of basil plants is 178 days. The first harvest expected 51 days after planting. The last harvest expected 49 days after planting. The last harvest sounds wrong, but we have a lot more data on first harvest than on last harvest. A planting has to be marked as finished before we know that a harvest was the last.
that looks like the basil plants hang on a long time in people's gardens while not being harvested anymore.
The predictions for the perennial plants aren't quite as good, e.g. strawberry which has " Median lifespan of strawberry plants is 15 days "