How Long Should You Run the Hose? Turning Gallons Into Minutes With Your Own Flow Rate
Every watering calculator eventually has to answer a practical question: how long do I leave the water running? The Watering Schedule Planner answers it in minutes, but only as well as it knows your hose. It has a Flow Rate box, in gallons per minute, that starts at 1. Almost nothing runs at exactly 1 gallon per minute: a garden hose on good pressure can deliver several times that, and a soaker hose a fraction of it. This guide shows how to measure your own flow rate, what to type in that box, and how the minutes change for the same bed.
Step 1: get the gallons
Take a 60 square foot flower border in a temperate climate, loam soil, in summer, after a week with half an inch of rain. With the Flow Rate left at 1, the planner gives:
- Weekly Need (before rain): 62.8 gallons.
- Water Saved from Rain: 18.7 gallons.
- To Apply After Rain: 44.1 gallons.
- Watering Time at 1 gal/min: 44 minutes.
- Optimal Frequency: every 2-3 days.
The number that matters is To Apply After Rain, 44.1 gallons. At the default flow of 1 gallon per minute the minutes simply equal those gallons, which is why the two figures match. Change the flow and only the minutes change; the gallons stay the same.
Enter the rain that actually fell that week in the Rain This Week box, ideally from a rain gauge in the garden, not an annual or monthly average for your area.
Step 2: measure your flow with a bucket
You need a 1-gallon container and a timer. The planner's own help text gives the conversion: time how long the bucket takes to fill, then divide 60 by the seconds to get gallons per minute.
- Set the tap where you normally run it. Flow changes a lot with how far the tap is open, so measure at your real setting.
- Attach whatever you water with: the wand, nozzle or sprinkler. A nozzle can cut flow sharply compared with an open hose end.
- Start the timer as the water hits the bucket and stop it when the bucket is full.
- Divide 60 by the seconds. Repeat once and average if the two readings differ.
Three example readings:
| Measurement | Flow rate to enter |
|---|---|
| Hose with wand fills 1 gallon in 18 seconds | 3.33 gal/min |
| Open hose end fills 1 gallon in 15 seconds | 4 gal/min |
| Soaker hose end fills 1 gallon in 4 minutes (240 seconds) | 0.25 gal/min |
A fast hose fills a 1-gallon jug quickly, so a few seconds of error in your timing matters. If you have a 5-gallon bucket, time that instead and divide 300 by the seconds; the larger fill gives a steadier reading.
For a sprinkler, the bucket test measures what the tap delivers but not where it lands. Set a few straight-sided cans across the area, run the sprinkler for a timed 15 minutes, and measure the depth in each with a ruler. The average depth tells you inches per 15 minutes; the spread between cans tells you how unevenly it waters.
Step 3: enter the flow and read the minutes
Here is the same 44.1 gallon border with each flow typed into the Flow Rate box. The planner shows whole minutes; the figure in brackets is before rounding.
| Water source | Flow Rate entered | Watering Time shown (per week) |
|---|---|---|
| Left at the default | 1 | 44 min |
| Hose with wand (1 gal in 18 s) | 3.33 | 13 min (13.2) |
| Open hose (1 gal in 15 s) | 4 | 11 min |
| Soaker hose (1 gal in 240 s) | 0.25 | 176 min (176.4) |
| Drip line, 20 emitters at 1 gal per hour | 0.33 | 134 min (133.7, about 2.2 hours) |
The same border needs anywhere from 11 minutes to about 2.9 hours a week depending on what is on the end of the tap. That is why copying someone else's "20 minutes a day" rarely works.
Then split the total across the suggested frequency. Every 2-3 days works out to about three sessions a week, so the border gets roughly 14.7 gallons per session: about 4.4 minutes with the wand hose, or about 58.8 minutes each time on the soaker hose.
Drip emitters: read the rating
Drip emitters are sold by their rated flow, commonly half a gallon, one gallon or two gallons per hour. Count the emitters on a zone, multiply by the rating to get gallons per hour, and divide by 60 for gallons per minute. Twenty one-gallon-per-hour emitters deliver 20 gallons an hour, which is 0.33 gallons per minute; that is the figure to type into the Flow Rate box for that zone. Ratings assume a certain water pressure, so a quick jug test under one emitter is worth doing on a new system.
Slow sources have an advantage: water has time to soak in rather than run off, which matters most on clay and on slopes. The downside is that run times get long, so a battery timer on the tap is worth having. If you use one, check it after power or battery changes; a stuck timer can run a zone all night.
A lawn, for contrast
Lawns cover much more ground. A 500 square foot lawn on clay, temperate, summer, with a quarter inch of rain comes out at 348.9 gallons needed before rain and 271 gallons after it. Left at the default flow of 1 the planner shows 271 minutes; with 3.33 entered for the wand hose it shows 81 minutes a week (81.4 before rounding), which on clay (the planner suggests 2-3 times a week) means splitting it into two or three long, slow sessions so it soaks in instead of running into the street.
Checking that the water went where you meant
Minutes are a means, not the goal. The goal is a moist root zone. After a session, wait an hour and push a trowel into the bed. Moist soil should reach several inches down for most flowers and vegetables. If only the top inch is wet, water longer or more slowly; if water is pooling or running off, use shorter sessions with breaks so it can soak in. Over the next few days, check again before the next session and skip it if the soil is still damp two to three inches down.
Early morning is the best time to water. Less is lost to evaporation, and leaves dry quickly, which helps keep fungal disease down.
What the planner does not cover
- A measured flow. It uses the flow you type and cannot check it. If you leave the box at 1, the minutes are just the gallons.
- Distribution. A sprinkler that soaks one corner and misses another still averages out to the right gallons. Use the can test.
- Pressure changes. Your measured flow drops when other taps or appliances in the house are running.
- Plant-by-plant needs. One plant group per run. A border of mixed shrubs and annuals has more than one need.
- Restrictions. Many water utilities limit watering days or hours, or ban sprinklers in a drought. Check the current rules before you program a timer.
For the numbers behind the weekly total, see how much to water a vegetable garden each week and how soil type and rainfall change your watering.
A note on safety around water
Keep extension cords, pumps and timers that plug into the mains well away from puddles and spray, and use outdoor-rated equipment on a protected outlet. Coil hoses after use so nobody trips over them, and empty buckets and cans afterward so they do not hold standing water where small children play or mosquitoes breed.
The short version
- Time a 1-gallon bucket fill at your normal setting and divide 60 by the seconds.
- Enter that in the planner's Flow Rate box, with this week's rain.
- Read To Apply After Rain for the gallons and Watering Time for the weekly minutes.
- Split it across the suggested number of sessions.
- Check the soil before and after, and adjust.
Five minutes with a bucket once a season makes every watering number on this site usable at the tap.