This free greenhouse watering schedule helps you plan watering for greenhouses with benches of tomatoes, peppers, seedlings or mixed crops. Enter how many benches you have and the temperature inside the greenhouse, and the tool works out litres per bench on each watering day and the total for the whole greenhouse, so you can water with a clear plan instead of guessing each day.
To use the tool, start by entering your main numbers in the boxes above. Check them once before you press the button, because a small typing error changes the answer a lot. If you are unsure about a value, use your best guess first, then change it and run the tool again to see how the answer moves.
The inputs matter because watering depends on the place, not just the plant. Heat, wind, sun and soil all change how fast water leaves the ground, and two gardens with the same plants can need very different amounts. That is why this tool asks for your own numbers instead of giving one fixed schedule for everyone.
The first result is the core number to remember. Write it down or take a photo of the screen, and use it at your next watering. If the number looks far from what you expected, check your inputs again, especially any number you entered in the wrong unit, such as centimetres instead of metres.
The second result turns that number into a routine you can follow through the week. A routine beats a single watering, because plants do best with steady moisture rather than a flood one day and dry soil for the next five days. Mark the watering days on a calendar until the routine feels natural.
For example, 4 benches at 28 degrees need about 14 litres each per watering day, which is 56 litres for the whole greenhouse.
A closed greenhouse on a sunny day can reach 40 degrees even when it is cool outside, and plants inside drink far more than the same plants outdoors. Opening vents early in the morning lowers the temperature and the water demand, and it also cuts disease risk.
The most common mistake is watering a greenhouse in the evening and then closing it up. Warm, wet air overnight invites fungal disease, especially on tomatoes and cucumbers, so morning watering plus open vents is the safer routine in most greenhouses.
Always check the soil before you water, even when the tool gives you a schedule. Push a finger a few centimetres into the soil. If it feels dry at that depth, water. If it still feels damp, wait a day and check again. This simple check catches rain, shade and cloudy days that no calculator can know about.
Water in the morning when you can. Morning watering gives leaves time to dry during the day, which lowers disease risk, and plants have water ready for the hottest hours. Evening watering is the next best choice, but try to water the soil rather than the leaves, especially for plants that suffer from mildew.
In hot weather, add mulch and shade where you can. A layer of straw, compost or bark on the soil surface slows evaporation a lot, and it keeps the soil cooler during a heatwave. Pots grouped together shade each other and dry more slowly than pots standing alone in full sun and wind.
Remember that this tool gives general garden guidance, not advice for a farm or a commercial crop. Your local soil, wind, mulch and plant variety all shift real water needs. Use the numbers as a starting point, watch your plants for a week or two, and adjust up or down until the routine fits your garden and your climate.