Scheduling crops to bloom on time is quite stressful for production managers. All those white lilies needed for Easter are useless the day after (well, not quite...but certainly not as useful). If those lilies are sold the day after, it'll have to be at a greatly reduced price—a price that might not cover the costs of growing them and bringing them (late) to market.
There are many holidays throughout the year, and most of them require floriculturists to stick to those tight schedules. But aside from those busy moments, floricultural work isn't very stressful for most of those involved. Processing and harvesting flowers can actually fall more on the "boring" side of the stress continuum. That's right—harvesting flowers isn't the titillating, electrifying, daredevil adventure you signed up for.