A set-it-and-forget-it approach to irrigation is a guaranteed way to either drown your plants or waste your entire rainwater harvest. As the seasons shift, so do the evaporative demands of the atmosphere and the biological needs of your garden. You must adjust your watering schedules accordingly.
Spring: Waking Up
In early spring, temperatures are cool, and the ground is often still saturated from winter snowmelt or early rains. Your plants are waking up, but their transpiration rates are very low.
- Action: Keep automated timers off. Rely entirely on natural rainfall. Only spot-water new transplants or seeds that are in the top half-inch of soil. Allow your rainwater tanks to fill completely during this wet season.
Summer: The Peak Demand
This is when your rainwater harvesting system proves its worth. Temperatures soar, days are long, and plants are actively producing fruit and explosive vegetative growth.
- Action: Turn on your automated systems. Water deeply and infrequently in the early mornings. Pay close attention to the weather forecast. If a massive summer thunderstorm is predicted, manually delay your irrigation cycle by a few days to avoid wasting tank water on soil that nature is about to soak.
Autumn: Tapering Off
As the days shorten and temperatures drop, plants begin their transition into dormancy. They stop producing new leaves and focus energy downward into their root systems.
- Action: Systematically dial back your watering frequency. If you were watering three times a week in August, drop it to twice a week in September, and once a week by late October. Overwatering in autumn can encourage late bursts of tender new growth that will be instantly killed by the first frost.
Winter: The Deep Sleep
In climates that experience hard freezes, active irrigation ceases entirely.
- Action: You must winterize your system. Drain all above-ground drip lines, disconnect hoses, and bring automated timers indoors so they do not crack when water expands as ice. Shut off the outflow valves on your rain barrels.
- Note on Winter Watering: If you live in a dry, cold climate that doesn't get snow cover, you may need to drag a hose out once a month on a warm day to give your evergreen trees a deep soak so they do not desiccate over the winter. Always drain the hose completely when finished.
Conclusion
By mimicking the natural seasonal flow of water, you encourage your garden to align with its natural biorhythms. You save massive amounts of water in the shoulder seasons (Spring and Autumn), ensuring your tanks are full when the brutal heat of Summer finally arrives.