Overall houseplant sales have quadrupled over the past four years to make up 10 per cent of overall turnover at Camden. The garden centre's café has a themed cacti menu including cactus-leaf tortilla and cacti mocktails. Chris Pugh's Cacti in Derbyshire is supplier of many of the cacti and succulents.
Hulatt suggests some people expected the "urban trend" to drop off but he says indoor plants are going from strength to strength. Pots and compost associated sales also bring in large amounts of income and sales are now year-round rather than having peaks.
Camden is "lucky" to be in the city rather than in the country, like most garden centres, so it can sell to flat and student accommodation dwellers as well as office workers in a younger demographic, with typical customers now 30-50, Hulatt explains. Buildings are going up near the centre, giving more chances for sales. Meanwhile, collectors are growing and asking for rarer plants.
Senior planteria assistant Vicky Jameson says sourcing unusual cacti and houseplants makes the difference over retailers such as supermarkets and Ikea. Toby Davies is planteria manager and deputy manager of the centre. Hulatt says having them rather than general staff look after houseplants, as in some garden centres, makes a big difference to sales.
Jameson says people see unusual plants on social media and ask for them. Hulatt says promotion of the health benefits of indoor plants for stress relief and air quality has helped to build the trend.
He has expanded the houseplant area twice in the past two years and may do so again. Linger time is important so customers can browse houseplants. They do not get this if the indoor planteria is near the till, as in many garden centres.
Hulatt says gift selling and catering competition is strong, but houseplants are a point of difference for the centre, especially unusual ones in different varieties and sizes.
Low-maintenance is a big selling point, which differs from the last big plant trend, grow your own, which plateaued because of a lack of time and space for many. Online sales of houseplants have been high, but garden centres can take a greater share if they have the range, he insists.
Bromsgrove-based Pugh's Cacti owner Chris Pugh says he has seen a trebling of the amount of succulents supplied into garden centres over the past 18 months. They are "friendly and architectural" rather than "spikey" cacti, he explains.
However, he says there are no other UK wholesalers of any size and the main suppliers are Dutch wholesaler Edelcactus and grower Kwekerijj Ubink, but even they have demand-driven shortages of young plants, which come from Italy, the Canaries and North Africa.
Plants take 18 months to reach saleable size. Pugh, who grows on hundreds of thousands a year, says echerveria, haworthia and crassulas are most in demand. He supplies clothing retailer Urban Outfitters with plants, which he says suit the 20-something "lifestyle" image of the company. The trend, driven by the internet, has two or three years to run, he suggests, but some garden centres "aren't on the ball".
Air plants, cacti, bromeliads, sanseveria and unusual plants are all collectible. Fittonia is a star performer, as are monstera. Common plants such as kentia palm and yucca are less desirable. Margins of more than 60 per cent are achievable and sales are now evening out year-round rather than having peaks in January, December and the run-up to Mother's Day.
Hulatt says supplier Javado makes sourcing plants easier without having to deal with Dutch auctions. Arnott & Mason in New Covent Garden Market is another supplier.
The category almost died in garden centres a few years ago as other retailers took the market, but now Hulatt sees no end to the trend. He adds that foliage houseplants have a long shelf life and flowering houseplants and planted arrangements of events such as Mother's Day are more difficult for garden centres to sell now.
Camden Garden Centre, winner of the best planteria award at the Horticulture Week Garden Retail Awards earlier this year, is currently promoting its August cactus festival through a series of events and workshops.
Marcus Cousins, horticultural manager at Ayletts Nurseries in St Albans, says houseplants have always been very strong at the centre and sales hold their own because they already do so well, while future growth is "about educating the customer about how to use them".
For instance, he says there are other options than Phalanopsis orchids and the air-cleaning benefits are underplayed. "We know trees are good for carbon but we're not good at educating on how to use houseplants. They do it better in Europe."
Top houseplant sellers by number sold:
- Succulent 5.5cm
- Succulent 8.5cm
- Cacti 5.5cm
- Pug cacti 11/12cm
- Cacti 6.5cm
- Fittonia Verschaffeltii 8.5cm
- Fittonia mix 8.5cm
- Spathiphyllum 'Chopin' 9cm
- Adiantum raddianum 'fragrans'
- Succulent Lithops 5.5cm
- Maranta tri-colour
- Asparagus setaceus (plumosus)
- Tillandsia mix 3cm
- Nephrolepis exaltata 'Green Lady'
- Asparagus plumosus
- Money plant
- Air plants
- Pilea peperomioides 10.5cm
- Spathiphyllum 'Sweet Chico' 13cm
- Calathea Luxe
- Chamaedora palm
- Oxalis triangularis 'Mijke Pink' 12cm
- Asplenium nidus 'Crispy Wave'
- Carnivorous plant mix 8.5cm
- Dracaena fragrans 11cm
- Iresine herbstii
- Sagina subulata 5.5cm
- Phlebodium aureum 'Blue Star'
- Lucky bamboo spirale 5cm
- Monstera pertusum 19cm
- Nephrolepis exaltata 'bostoniensis'
- Crassula ovata 5.5cm
- Peperomia 'Smith Collection'
- Reindeer moss
- Chamaedorea elegans 17cm
- Tradescantia 18cm
- Tradescantia spathacea 'Sitara'
- Monstera deliciosa 17cm
- Aloe vera
- Ficus elastica 'Abidjan'
- Ferns 6cm
- Senecio herreianus 6cm
- Hoya kerrii 6cm
- Hypoestes phyllostachya 8.5cm
- Spathiphyllum 'Chopin' 6.5cm
- Hanging plants mixed
- Succulent hanging mix
- Dracaena marginata
- Crassula 'Magical Tree'
- Spathiphyllum 'Sweet Gino' 13cm
- Spathiphyllum 'Pearl Cupido' 7cm
- Bonsai 15cm
- Chlorophytum mix 12cm
- Echinopsis subdenudatum 5.5cm
- Muehlenbeckia complexa 11cm
- Aloe cosma 8cm
- Sansevieria cylindrica
- Bromelia Mix
- Aeschynanthus 15cm
- Monstera obliqua 12cm