One tree at a time

The first application of our Sponsh material is integrating it into a tree protector (or stem guard), for application in reforestation and orchards. This self-watering tree protector absorbs water from air at night. During the day, the protector autonomously releases the water to irrigate the young tree. Ensuring it can survive the first harsh summers and grow into a self-sustained large tree.

Main features

  • Zero energy: water uptake and release are driven by the natural temperature cycles of day and night. No mechanics and no electricity needed.
  • Off-grid: the water is taken from the air and released at the roots. No water pipes, irrigation networks or electricity lines are needed. Especially useful in remote projects, away from water reservoirs.
  • Biodegradable: the materials used in the tree protector (inserts) are fully biodegradable. No need to remove them after use. The expected lifetime is 2-3 years.


  • Substantially increased survival rate: from 20-30% to 80-95%
  • 60-80% cost savings compared to alternatives, like irrigation systems of underground water reservoirs. We expect to offer Sponsh Tree Protectors to end-users for approximately EUR 1,750 ex VAT (1,000 pieces).
  • Longer ‘planting window’, because planting can be done earlier in the dry season. This way, more projects can be carried out per year per organization
  • Possibility of reforestation and development of dry regions that are currently not eligible due to (too) limited rainfall
  • Possibility to plant younger trees or even seeds

Climatical conditions required

It is expected that the tree protectors will benefit Mediterranean climates most (Köppen Csa and Csb). For the material to absorb and release water, the following is required:

  1. Relative humidity at night higher than ~70% for a number of hours, so that the textile is able to (have time to) absorb water molecules from the air. This is the case in most coastal areas (<150 km from the coast)
  2. Daytime temperature in the tree protector is higher than 32 degrees. This is required to release the water from the system. Note that outside temperatures do not need to reach this temperature, several hours of sunshine will heat them up sufficiently (you could compare it to leaving your car in the sun)

* Please note that we are currently in the development phase, improving the material, scaling it up, testing it in real life conditions and adjusting it. The information above is based on our best estimates but no rights can be derived.