Next year may well see biodegradable pots and trays breaking through to mainstream horticulture, if their prevalence at recent trade events such as Four Oaks and Horti Fair is anything to go by.
Such pots are nothing new, of course. Norway-based Jiffy has been manufacturing "grow-through" pots for the commercial market for over half a century. But it has proven difficult to produce these types of pots and trays that were robust enough for automatic handling by machines designed for tougher man-made materials.
The new-generation products made from natural fibres do not suffer from this shortcoming. Some also match another advantage of synthetic pots in that they can be printed on.
Jiffy has introduced the Speedypot degradable pot range. The upper section of the pot is rigid enough for mechanical handling and printing, but it will still allow roots to grow through the pot wall lower down - this ensures that "air-pruning" avoids the risk of root spiralling and pot-bound plants.
According to Jiffy representative Anno Hermes, the company's products tick other sustainability boxes too. "Jiffy pots were originally peat pots - now they are peat-free pots and they break down faster," he says.
French company Fertil is another long-established manufacturer of pots from biodegradable material - in this case, spruce fibre and peat - for both retail and professional markets.
According to commercial director Eric Grange: "Some municipalities in France have gone completely from plastic to degradable pots. They are about twice as expensive as conventional pots, but you save time and don't have a problem with waste. I'm surprised more British authorities don't use them."
He describes sales to the professional market as "stable" but adds: "Our growth now is in the retail market, where people are more ready to buy a sustainable product."
The company is trialling a more customer-friendly end product that incorporates a clear sleeve made from maize, which is already finding some favour in the US, Grange adds.
Unlike the Jiffy and Fertil ranges, biodegradable products from other manufacturers are designed to be used in the same way as conventional products, then disposed of separately to the plant - usually by composting.
Among them is Netherlands-based Desch Plantpak, which has launched a range of biodegradable flower pots, trays and packs under the D-Grade Bio brand, which cover most market niches.
Chief executive officer Peter Marteijn says: "We have carried out research together with key partners into alternative raw materials that are good for the environment and offer a solution to the problem of waste.
"Biologically degradable flowerpots have a much higher value. They play a role in the climate discussion and contribute to solving the CO2 problem. But we will carry on with research and development, because in the field of sustainability there are still huge advances to be made."
In addition to standard ranges, the company will consider producing bespoke D-Grade Bio designs in volume, he adds.
The company has also enhanced its conventional pot range with a redesigned 13RX deep rose pot, which now includes a label slot.
Danish firm Flora Deco has launched a biodegradable pot range which the company says is sturdy enough to be used in conventional potting machines.
And Poppelmann Plastics - which owns the Teku range of around 700 products in 200 formats for both the retail and professional grower markets - is also moving into the biodegradable pots market.
The 100 per cent organic Bio Pots are made of maize and potato starch. "It's still a side market for us, though that may change," says export sales manager Karin Nordlohne.
Meanwhile, Ipswich-based supplier Calipso (Roast) launched a range of biodegradable flower pots in May this year - confusingly, also called Bio-Pots. These come in black, beige and mocha colours and a range of formats, from conventional round pots with 10.5cm, 15.5cm and 19cm diameters to more unusual curved-wall and rounded-square cross-section designs.
According to a company representative: "They suit plants like Azalea and are attractive enough to put on the windowsill then plant out directly in the garden. But being biodegradable means there is a limit to the colours available."
The pots are being sold to both growers and wholesale suppliers to garden centres, which may want to plant them up themselves. On the conventional side, Teku printable pots are available up to 17cm diameter. "The market for printed pots is growing, whether that's to reinforce the brand with the customer or to provide care instructions," she says.
Modiform UK sales manager Tim Davis confirms this trend. He says: "Printed pots are a growing market - we have doubled the volume we do. But it may add 50 per cent to the price of a small pot and the price will be higher - though not hugely - the more colours you use."
The company has invested in its own colour printing equipment, allowing it to cut down on lead times, he adds. One outcome of this has been a short-term promotion for kitchen windowsill herbs for Tesco, which provided the colourful designs.
Printing and branding
Modiform has taken printed pots one step further with Charity Pots, a partnership with Lanarkshire-based Reynard Nursery, which has grown and sold on 100,000 plants in the charity-themed pots for sale through Dobbies Garden Centres, making £1,500 for a breast cancer charity.
Young Plants has already adopted the Charity Pots format and the partnership is currently in discussion with other growers with a view to expanding the concept next year. The pots are available for £28 for a minimum order of 1,000.
Elsewhere on the market, there are "tweaks rather than sweeping changes", says Davis.
Horticultural supplier PG Horticulture owner Paul Greenhalgh explains: "It's a very price-competitive market, with a plethora of suppliers, and each has to look after its customers to hold onto them. But everyone needs pots so overall the market is pretty stable."
The company was taken over by German firm Meyer in June. "We are taking on extra staff and introducing a comprehensive range of pots that will run from 1.5 litres to big pots for trees up to 750 litres," Greenhalgh adds.
Meanwhile, core pot market lines are being refined for maximum ease of use and efficiency of space.
French manufacturer Soparco has come up with a novel solution to maximise space for larger pots, by staggering the heights within the tray. "This allows a trolley to be filled with 1.3-litre square pots, only five fewer than with one-litre pots," says company representative Julie Berthonneau.
Trolley space usage is also a prime consideration with the 0.37-litre square pot and tray format, which allows 90 pots to be racked on a conventional trolley, she adds.
And Teku's E2328/20 tray, with cavity format, allows 220 plants to be accommodated on a Danish trolley shelf while also maximising the growing media volume.
Side slits provide space for plant tags or carrying handles, which can be inserted automatically.
The company has also introduced orchid pots in clear plastic, with a detachable net pot within a format designed to meet orchids' unique growing requirements. They have already been successfully used in commercial growing.
But not all suppliers put a premium on innovation. For some, such as H Smith Plastics of Essex, prompt and reliable service is key.
The company - which specialises in selling to small to medium-sized growers - also continues to manufacture seed trays.
But according to company director Derek Mansell: "Now we also buy in and sell round pots, from 9cm to 40 litres, and that has taken off for us. We've had a very good year and grow-your-own has helped that.
"Our customers tell us they have been let down by other companies, but we have never been unable to supply a customer. We can mostly do next-day delivery, whether it's two cases or 200, and we're getting a lot of smaller orders over the internet.
"Much of this success comes down to simply keeping shelves stocked. It's no good saying to a grower, 'we can get that to you in six weeks,' when everyone wants it yesterday."
Caledonian Tree Company has introduced a retail version of its Air Pot, already well-established in the container-grown nursery stock sector. Made in Scotland from recycled plastic, the Terrace and Garden Potato Towers aim to benefit from the grow-your-own boom at retail.
Available in twin packs of 50-litre (for the Terrace model, with porous base) and 80- and 150-litre formats (for the Garden model, without base), these enable even gardeners with restricted outdoor space to produce substantial crops, either on hard surfaces or directly onto open soil.
Meanwhile, for growing tender crops under glass, Air Pots are available in 10-litre and 14-litre formats, in flat packs of threes and shallower than the hardy nursery formats.
According to director Jamie Single: "For 15 years we have just been supplying the trade - we weren't geared up to just sell five pots at a time. But we have been doing tests for the past two or three years."
The company has even launched a dedicated website, www.airpotgarden.com, to promote the range.
And Soparco has introduced a range of pots for retail in subtly varying colours, the result of a new industrial process, each with pluggable drainage holes allowing them to be used indoors and out.
Caledonian Tree Company 01875 835360
Calipso (Roast) 01449 740977
Desch Plantpak 01621 745500
Fertil UK 01948 770008
Flora Deco 0045 631 72300
H Smith Plastics 01268 733088
Jiffy UK 0870 366 7930
Modiform UK 07725 036736 (Tim Davis)
PG Horticulture 01379 873344
Poppelmann Plastics UK 01482 373930
Soparco 0033 233 733 011