Make a watering device


Make a watering device from a plastic milk bottle that can be used as a watering can or buried next to a plant to release water over a longer period of time.

  • Estimated time: 30 minutes
  • Location: Outdoors
  • School term: Early Spring, Late Spring, Early Summer, Late Summer
  • Level of experience: No experience needed
  • Subject(s): Science, Art&DT

Learning objectives

  • Design and make a watering device
  • Explore the different rates at which water will flow from the device
  • Encourage working scientifically - gather data and use observations to answer questions.

Essential background information


Wash out milk bottles well and remove labels.
Dry the outside before decorating. 

Equipment needed

  • Empty plastic milk bottles with lids – 1, 2 or 4 pint sizes
  • Junior hammer
  • Fine nails (of varying gauge) or bradawl
  • wooden board to nail into
  • Permanent marker pens
  • Stopwatch

Step by step

  1. Show the pupils a range of different sized watering cans. Some are too heavy once filled with water. Point out the head or ‘rose’ that creates a fine spray of water. This is useful when watering small plants that could otherwise be washed away.
  2. Fill a milk bottle with water and pour the water out with the lid off.  Ask the pupils if they could improve this design to make the water flow slower or have a finer spray. 
  3. Place the lid onto a wooden board, use a nail and hammer to make holes into the lid (adult help may be required).
  4. Experiment with the number and size of holes and time how long it takes for the water to pass out of the bottle. Observe how the spray can vary according to both these factors.
  5. Make a tiny hole in the handle of the milk bottle to allow air into the bottle. Explain this is to stop a vacuum that would prevent the water flowing freely. To test this theory try the device with and without this hole.
  6. Decorate the outside of the watering bottles with pens.
  7. Practise watering with the watering device. Remember to water the soil next to the plants, rather than the leaves. Water methodically along the row.

Hints & tips

  • Use different sized nails or a bradawl to produce varying sized holes.
  • Fill a watering device with water then bury it next to a thirsty plant such as a pumpkin, where the water will percolate into the soil over a longer period of time.
  • If you cut the base off, the bottle becomes a target or funnel for direct watering.
  • Use this activity as part of Grow Your Own Lunch class growing topic

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