Recycled self-watering device


Recycle your plastic containers to create this brilliant self-watering device and ensure the survival of your indoor plants!

  • Estimated time: 30 minutes
  • Location: Indoors
  • School term: All year round
  • Level of experience: No experience needed
  • Subject(s): English, Maths, Science, Art&DT

Learning objectives

  • Keep indoor plants watered  
  • Discover the absorbency of different materials
  • Observe the function of roots and stem in water transportation
  • Set up a simple practical enquiry with a comparative and fair test

Essential background information


Look at plants growing in pots indoors, what requirements do they have in order to grow well?

Investigate water transportation in plants and discover how we can observe this in action using this self watering device!


  • Empty plastic bottle with lid
  • Compost
  • Absorbent material (e.g. dish 'cleaning cloth')
  • Scissors
  • Hole making tool (bradawl or palm drill)
  • Small potted plant
  • Water

Next steps

  • You could use this self-watering device for sowing seeds, but make sure the compost is damp before you start.
  • Use this device to set up a practical enquiry - how can it be a fair test?
  • Can you identify the possible variables?
  • Experiment with different types of material to see which is most absorbent. Discover which will work best to keep the soil moist. Is cotton string better than wool?
  • Try different 'growing material' such as garden soil or gravel. These are the first steps in hydroponics - check out the resource on this!

Step by step

  1. Remove the lid from an empty plastic bottle.
  2. Make a hole in the lid using sharp scissors or a palm drill (an adult may need to do this).
  3. Cut strips of dishwashing, absorbent cloth.
  4. Push one end of the cloth strip into the hole in the lid, pull half the material through.
  5. Cut the bottle in half (an adult may need to do this).
  6. Put the lid back on, coil the excess material into the 'top' half.
  7. Fill the 'top' half with multipurpose compost, covering the dishcloth material.
  8. Stand the up-turned, cut-off 'top' into the 'bottom' half of the bottle.
  9. Water the compost well.
  10. Make a hole in the centre of the compost and place your chosen plant in, press in extra compost to make it feel firm.
  11. Pour water into the lower part of the bottle and make sure that the absorbent cloth can reach it.

Hints & tips

  • Choose a healthy plant to start with!
  • Make sure you have plenty of absorbent material in the section with the compost.
  • Place your self-watering device in a sunny location.

We've won awards!

Winner of the Drum Marketing Awards 2017
Winner of the ERA 2017 awards
Winner of the Third Sector 2017 awards