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Garden Watering Scheduler
Tell us your crop, soil, bed size and this week’s rain. We’ll work out how many inches your beds still need, convert it to gallons, and split it into deep, root-building waterings.
Your beds
The schedule updates as you type.
How this is calculated
Like a lab worksheet — every step is shown so you can check the working:
- Net inches per week:
max(0, 1 × crop factor × soil factor − rainfall)— the classic 1-inch-per-week rule, adjusted for your crop and soil, minus what the sky already delivered. Never below zero. - Gallons per week:
net inches × bed area (sq ft) × 0.62— because 1 inch of water over 1 square foot equals 0.62 gallons. - Worked example: tomatoes (1.2) in loam (1.0), a 32 sq ft bed, 0.25 in of rain →
max(0, 1×1.2×1.0 − 0.25) = 0.95 in→0.95 × 32 × 0.62 = 18.8 gallons. - Watering sessions: 1.5 in or more → 3 deep waterings; less than that → 2 deep waterings; zero → skip watering this week.
- Per session:
total gallons ÷ sessions(andnet inches ÷ sessions).
Understanding the factors
| Crop group | Factor | Why |
|---|---|---|
| Tomatoes & peppers | 1.2 | Large plants, heavy fruit load, high transpiration |
| Cucumbers & squash | 1.15 | Big leaves lose water fast |
| Leafy greens | 1.0 | The baseline — the classic 1 inch per week |
| Root vegetables | 0.9 | Steady but moderate drinkers |
| Beans & peas | 0.85 | Fix their own nitrogen; modest water needs |
| Herbs | 0.7 | Many prefer slightly dry conditions |
| Soil type | Factor | Why |
|---|---|---|
| Sandy | 1.2 | Water drains through quickly — needs more, more often |
| Loam | 1.0 | The ideal balance of drainage and retention |
| Clay | 0.85 | Holds water tightly — needs less, but water slowly |
Sources & assumptions
The 1-inch-per-week baseline and the 0.62-gallons-per-square-foot-per-inch conversion are standard figures published by US cooperative extension services. Crop and soil factors are planning estimates that summarise extension watering guidance — real needs vary with temperature, wind, mulch and growth stage. Treat the schedule as a starting point and adjust by checking soil moisture 2 inches down.
Drip or hose? Work out what suits you
How you deliver the water matters as much as how much — compare drip irrigation with hand watering for raised beds.
Read the comparison guideWatering FAQ
How much water does a vegetable garden need per week?
Around 1 inch of water per week is the classic extension-service rule of thumb for vegetables, measured as rainfall plus irrigation. Thirsty crops like tomatoes want a bit more; herbs and established beans want less. This scheduler adjusts that baseline for your crop and soil.
Why water deeply and less often?
Deep watering soaks the whole root zone and encourages roots to grow downwards, where the soil stays moist longer. Light daily sprinkles keep roots near the surface, where they dry out fast and suffer in hot weather.
How does rainfall count towards the total?
One for one: an inch of rain is an inch of water your beds received, so it is subtracted from the weekly need. The result never drops below zero — extra rain simply means you skip watering.
What if it rained more than my garden needs?
Then the net need is zero and you water nothing this week. Soggy soil suffocates roots and invites disease, so let the beds drain and recheck soil moisture before the next scheduled session.
Do sandy and clay soils really need different amounts?
Yes. Sandy soil lets water drain straight through, so it needs more water (factor 1.2) applied a little more often. Clay holds water tightly, so it needs less (factor 0.85) — but apply it slowly so it soaks in rather than running off.
Should I water in the morning or the evening?
Morning is best: leaves dry quickly as the day warms up, which reduces fungal disease, and less water is lost to evaporation than at midday. If mornings are impossible, early evening is the next best choice.