Franka Kruse-Gering

June 16, 2026, 12:17 pm | Read time: 4 minutes

How Much Water Do Plants Really Need?

Many hobby gardeners underestimate how different the water needs of various plants can be. While newly planted perennials, vegetables, or potted plants require regular watering, established shrubs and trees often need significantly less.

The general rule is: Water less frequently but thoroughly rather than distributing small amounts daily. Frequent shallow watering causes plants to develop roots mainly in the upper soil layers, which dry out particularly quickly. Deep watering, on the other hand, promotes deeper root growth and makes plants more resilient to drought.

Determine the Water Amount with a Simple Trick

When watering with a garden hose, it’s often difficult to estimate the amount of water used. A simple bucket test can help. Place a bucket with a known capacity–such as 10 or 20 liters–under the hose. Measure the time it takes to fill the bucket. This way, you can determine the hose’s flow rate and better estimate how long specific plants need to be watered in the future.

Since water pressure and flow rate can vary depending on the connection, this method is much more reliable than mere guessing.

Properly Watering the Lawn

Especially in summer, lawns require relatively large amounts of water. Instead of watering briefly every day, the lawn should be thoroughly watered once or twice a week, explains Dr. Harald Nonn, former chairman of the German Lawn Society, in response to a myHOMEBOOK inquiry.

A practical check can be done with a straight glass or a shallow can placed on the lawn during watering. If it collects about 15 to 25 millimeters of water, the lawn has generally received enough moisture. This corresponds to approximately 15 to 25 liters of water per square meter.

The Best Time to Water

The early morning hours are considered the ideal time for watering. At this time, the soil and air are still relatively cool, so less water evaporates than during the hot midday hours. Additionally, the water is already available to the plants when temperatures rise during the day. If you don’t have time in the morning, you can use irrigation computers or timers.

Watering in the evening is also generally possible. However, plants and soil remain wet longer, which can promote fungal diseases under certain conditions.

Also interesting: What is a drip hose and how is it used?

Why the Midday Heat is Unsuitable

During hot midday hours, some of the water evaporates before it even reaches the roots. This makes watering less efficient, and plants can still suffer from drought stress despite watering. Additionally, cold water on a highly heated ground or in heated plant containers can cause additional temperature stress. Those who water at midday often need to use more water to achieve the same effect.

More on the topic

During prolonged drought 12 Tips to Save Water in the Garden

Plant Care 7 Mistakes in Garden Watering–and How to Avoid Them

Rainwater is Often the Better Choice

Many garden plants benefit from rainwater. It is generally softer than tap water and contains less lime. Particularly lime-sensitive plants like hydrangeas, rhododendrons, or blueberries appreciate this with healthier growth. A rain barrel or cistern also helps save valuable drinking water and makes garden watering more sustainable.

Keep Water in the Soil Longer

Not only watering itself but also soil care affects the water balance in the garden. Instead of regularly digging up the soil, it is advisable to gently loosen it with a hoe or cultivator. This preserves the soil structure and allows water to penetrate deeper layers more effectively.

Additionally, a mulch layer of grass clippings, leaves, or bark material helps significantly reduce evaporation. At the same time, the soil remains loose and moist for longer.