Getting to the root of the matter!

Q.1 What are some typical problems when trying to introduce innovative products to the horticultural sector?

I choose the ‘Superoots’ (the Air-pot) manufactured by The Caledonian Tree Company (CTC Ltd) as an example. The new container offers advantages in terms of finished plant quality but is more expensive than ordinary pots.


It takes time for growers to appreciate the practical advantages of the new pot over several production cycles and even longer. Growing plants is a conservative business, having arrived at successful production techniques for specific plants, growers are naturally loathe to make changes and to spend more money. They also want to know what plant varieties benefit most from the new pot.

In the meantime, understandably, supply companies of conventional containers can advise their grower clients against new products. This is particularly true in Italy where representatives of supply companies often tend to provide the technical advice.

It takes even longer for marketing and sales to address all relevant market segments (production, landscaping, wholesale and retail) and to obtain a premium price also from customer willingness to pay more for the extra plant quality obtained using the new container.

This type of innovation tends to make slow but steady progress on the market through continued technical trials, commercial uptake and promotion. The manufacturer/ supplier needs substantial resources and great perseverance to keep pushing the merits of the new product internationally.

Suddenly, often after a long and protracted period of time, the momentum of its utilization and promotion breaks down the resistance and the product enjoys faster and wider market acceptance.

This long introduction time-lapse is more common with important innovation since it requires reform of traditional thinking and practice. Other similar products are then given an already created ‘acceptance platform’ on which to compete.

I have followed experimental trials and commercial take-up of ‘Superoots’  Air-pot for some years

Q. 2 What environmental influences does a root system experience?

Roots are subject to abiotic stress factors, from soil-moisture to temperature, gaseous exchange, pH, mineral elements, organic chemicals and ionic charge. Added to this is mechanical and hydraulic stress exerted on roots by periodic water stress and drying of the soil. Biotic stress factors include: soil microorganisms, bacteria, fungi, viruses, nematode worms and insect larvae.

When this complex ‘plant stress dynamic’  arrives at a natural balance, albeit temporary and within certain limits, plants are able to grow and thrive. Much less research has been made on roots and the root-zone in comparison to the aerial parts of plants.

In the case of ornamentals, positive effects on growth are obtained by utilizing different types of containers, cultural regimes and plant chemicals from fertilizers to anti-stress substances. There has been a slow and steady increase in the use of containers or ‘Air-Pots’ with punctured side-walls that cause ‘air-pruning’ of roots as a result of stress.

Q.3  What effect does air-pruning have on root systems?

The stress suffered by the root tips near the air holes, stimulates the synthesis of abscissic acid (ABA) which acts as a signal mediating a variety of responses. The most important result for the grower is the differentiation and growth of new outward pointing fibrous roots along the original roots to the base. These fibrous roots are all potential feeder roots. The response can be so strong according to Caledonian Tree Company Ltd that from any one original root that is air-pruned, 5- 10 new fibrous roots grow out into the substrate. This is a huge multiplying effect that results in the fast development of a thick fibrous root system, able to take up more water and minerals than a conventioned grown root system and better resisting transplant stress.  It also allows a reduced number of transplant stages and avoidance of spiral rooting.


The response varies with species but the general overall result is very positive, even in genera such as Eucalytus that ordinarily produce very dominant tap roots. More trials with air-pruning containers should be made on growing tropical plants in these containers e.g. Ficus spp, Palms, Dracaena, Croton etc

Q. 4 What do ‘Superoot’ containers (the Air-Pot) consist of?

They are made from rolls of pre-determined lengths to create a cylindrical container. This makes it easier to wrap around the sometimes irregular root balls of large trees. Some smaller sizes are available already made up which contain a bottom net. The profile of this recyclable polyethylene material consists of closed inward pointing cones and open-ended outward pointed cones. The former guide the roots toward the air holes. The material is based on an original Australian patent and the name ‘Air-Pot’ is registered by CTC Ltd.

Q. 5  After many years of grower scepticism regards the cost effectiveness of Air-Pots the predominant opinion today favours their use, especially in the production of high quality woody plants.What have growers found to be the advantages?

Air-Pots reduce production time also improving the final quality of the plants. Growers can now produce young stock from seed or cuttings in small Air-Pots (Air-Cells) through to medium and mature trees with large rootballs. Root spiralling is avoided. Jamie Single, CEO of CTC, adds that 30% more compost by weight can be packed into their Air-Pots (due to the light plastic protuberances). This means that plants can be left to grow in the same container for 2 years rather than one. Plants can be stored for much longer periods without suffering damage and an good fibrous root system reduces transplant stress. Greater air density in the substrate favour microorganisms that in turn guarantee healthy root growth. Air-Pot See also the quality trees grown by Stairway Nursery (UK)

Q. 6 Following behind CTC with the same principles?

The same principles are behind the ‘Uniko’ container by Italian Company Barghini Plast 2 Srl, Pistoia, Italy (in liquidation). In this case, the inward and outward pointing cones are flatter and the plastic is more rigid. A plus point is a bottom ring of rectangular holes for lifting puposes.  The ‘Uniko’ design uses a mixture of high and low density recycled polyethylene and comes in pannels that clip together. The exception is a small 2 litre container that consists of a single pannel plus base. The pannels can be produced in a variety of colours.


Edward Bent ©2012 | HORTCOM



  1. Pingback: Innovation takes time | hortcom

  2. Michael says:

    A couple of years ago I saw a product similar to the Air-pot, but it was a biodegradable wrap, so that you couple either trim the roots if they got too aggressive, or enlarge the circumference of the pot. Would anybody know what that product was and provide a link? Thanks in advance.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s