What Is This Black Spiky Air-Pot Container?

All you wanted to know and didn’t dare ask about the Air-pot!

What is an Air-pot?  A really nifty plant pot designed to keep trees on their toes.  It’s a root engineering device

They are the essential Eucalyptus growing environment (other than the ground!).

Where did it come from?  Glasgow – but that’s not actually what you meant, was it?   Answer = Australia

Why was it invented?   Back in the 1950’s or so, the Australians discovered the art of growing trees in pots and began planting Eucalyptus in their High Streets and towns. Fast forward 20 years to the 1970’s and these two tonne Eucalypts began falling over and squashing things like cars and people.

Naturally, the townsfolk became a teenzy bit miffed and demanded their council fix the problem.  They in turn engaged a brilliant local Aussie nurseryman to solve the toppling trees and after a bit of trial and error, he invented the ‘Rocket Pot’.  So called because when you use them, the trees grow like… you guessed it… a rocket.

We Brits just call them Air-pot Containers!

What’s wrong with using a traditional pot?  Eucalyptus are a fast growing hardwood tree.  When grown in a traditional smooth-walled pot, the roots hit the wall and begin to spiral, resulting in a hardwood corkscrew root ball.  When planted, the anchor roots never move out into the surrounding soil, to stabilize the tree. Instead, with every passing year, they remain as a tight hardwood spring, supporting an increasingly large tree above ground.

Then, typically on a wet and windy, winter night, with no supporting cast of oaks or fellow deciduous trees, the Euc. falls over.  Eucalyptus grown without air-root-pruning are a liability, a ticking time-bomb and quite frankly, the practice should be banned.

Interesting factoid: I have been told that the trees supplied for the Olympic park were specified to be Air-pot container grown, presumably to guarantee their establishment, survival and longevity

Why use an Air-pot – what does it do to the plant?  Roots don’t like fresh air, they like to hide away underground, in moist, dark and damp conditions with their mycorrhizal fungus (but we don’t judge them for that).  When exposed to fresh air, that bit of root gets singed, dehydrated and effectively pruned. In turn, the living root further back up the system is encouraged to branch and produce new roots.  Ultimately the clever engineering of the pot fashions a vibrant root ball similar in style to a baby’s bottle brush, where all the tree roots emanate from the central crown in a radial fashion.

Air-pot container grown  =  Safe and Stable Root-system

Warning:  Never buy a Eucalyptus that has not been grown in an Air-pot.

Please note: you do take the pot off before planting or potting on. Do not plant your tree in the ground with the pot still on. The tree is not root-bound (that’s what the pot prevents); you have to unscrew the green screw to release the rootball.

For more information, see our Air-pots page and scroll down to “Why Air-pots?”