Bloom Clock/10 plants per month
An easy, "finite" way to contribute to the Bloom Clock is to pledge 10 logs per month. With 10 logs from any particular region, we can at least make a visual key page worth looking at. Contributing to the bloom clock in a basic manner does not require any expertise in plants, but rather only involves simple observation and a search through the visual keys.
Using the visual keys
If there is already a visual key for your region (there almost certainly isn't yet), just browse by month, color, and plant type to identify the plants you saw, and log them (four tildes is all you need). If there isn't, you'll need to pick the key that you think is most likely to have similar plants to those in your region, and perhaps adjust the month (for example, if something is blooming in March in Pennsylvania, it might be blooming in February in Georgia or April in Quebec).
Using the text logs
If you know your plants, there are text log pages for each solstice-to-solstice period (we may need to move to a quarterly system soon though, because the log pages are getting too long). In this case, you can just add your four tildes under the plant's scientific name (it will later be moved to the plant's log page as the text clocks are archived). Contributors can add as many listings of new plants as they have time for.
Asking for identification
If you can't find a plant on one of the visual keys, and have a photograph of it, you can use the Unknown Plants page. The template used on that page should be self-explanatory.