August 13, 2026 · Updated September 12, 2026

How often water tubing should run in your garden

A drip timer runs your tubing on a fixed schedule, wet bed or dry. Your plants draw water from the soil, and soil dries at a different rate in every bed. Run the tubing when a bed reads dry, and skip the run when it still holds water. A fixed daily timer can't tell the two apart.

What a fixed timer misses

A timer knows the clock and nothing else. Whether a bed needs water depends on its soil mix, its depth, how much sun it takes, how large the plants have grown, and how much rain fell this week. Two beds side by side rarely dry at the same pace. A schedule set to keep the driest bed alive will flood the steady one next to it.

The fix is to run each zone off what its soil reads. That is the same logic behind running a valve only for the zone that needs water and behind pointing a drip system at the dry beds.

How our beds dried over one summer

In our own garden the raised beds and the ground bed carry probes, and they did not move together. Raised bed 3 ran from 32% on July 13 to 62% on August 21. The ground bed covered that same 32% to 62% range, though it bottomed out on August 6, weeks after the raised bed did. Raised bed 1 barely moved, staying between 39% and 54% all summer. Raised bed 2 held 36% to 57%.

One timer serving all four would have overwatered the steady bed to keep the swingy one from drying out. Rain widened the gap further. July gave us 10.89 inches. A timer running every morning through that month would have poured water onto beds that were already full.

Tie run frequency to what the bed reads

A soil probe in the bed reads capacitive moisture as a percentage. Siltwell flags a bed once its two most recent readings both sit below the threshold. The default is 25%, and you set your own value per bed. That warning is your signal to run the tubing for that bed. It alerts you and leaves the valve for you to open.

Match the threshold to each bed. Our raised beds and ground bed sit in different bands, so a single number would misfire on one of them. The way to pick it is covered in setting a per-bed threshold from a baseline.

Rain gets weighed at the garden level. Siltwell tracks rain three days back and a day or two ahead. Once either window reaches 5 mm, it tells you to hold the garden's run. That is how you skip a run that rain already covered. The soil probe answers which bed is dry, and the rain signal answers whether to water the garden at all.

How long a run should last

Run long enough to wet the root zone, then read the probe an hour later. Suppose a bed reads 20% before a run and climbs to 45% after. That tells you the run reached the roots. If it barely moves, the run was too short, or an emitter near the probe is clogged. Deeper beds and faster-draining mixes need a longer run to reach the same number, which is the same idea as watering to the root zone with a hose.

Start today by setting a threshold for each bed with a probe, then let the dry alerts and the rain holds set your run frequency instead of a calendar. For beds without a probe, read one nearby bed and adjust for how much faster or slower it drains, using a per-bed probe reading as your reference.