GardenKitHow it works
Enter the total water depth you want for the week and the effective rain that actually reaches and benefits the bed. The remaining depth cannot fall below zero. Convert this depth over the bed area to water volume, then divide by irrigation efficiency to estimate the supply volume. Efficiency represents your own estimate of application losses. Sessions divide the weekly amount equally; they do not recommend when to irrigate. Runtime assumes the measured total flow stays constant. No forecast, soil sensor, runoff model or crop requirement is fetched. Adjust the target from soil moisture, weather and local advice.
Formula
Net depth = max (0, target − effective rainfall). Supply litres = area × net depth × 1000 ÷ (efficiency/100). Runtime minutes = supply litres ÷ litres per minute.
Example
For 3.6 m², a 25 mm target and 10 mm of effective rainfall leave 15 mm, or 54 L reaching the bed. At 85% efficiency, supply about 63.53 L. Two sessions need about 31.76 L each. With an 8 L/min system, that is 7.94 minutes for the week, or 3.97 minutes per session. Rain at or above the target yields zero additional irrigation.
Assumptions and limitations
Use product labels and local growing guidance. Defaults are examples. Assumptions use your inputs, not live weather or crop-specific prescriptions. Volume estimates exclude delivery and tax. Bag quantities round up.
Sources and assumptions
University of Minnesota Extension · Garden bed · University of Minnesota Extension · Water
Frequently asked questions
Are my garden measurements uploaded?
No. The tools save your current bed and settings in this browser. Clear this site’s data to remove them.
Does switching units change the result?
No. Dimensions stay in metres internally. Imperial views use feet and inches, cubic feet for bags and US gallons for water.
Are the defaults recommendations for my plants?
No. They are worked examples. Use product labels, crop requirements, soil moisture and local growing guidance.