Geothermal key to flower-growing success

Connie and Harald Esendam with the packaged gerbera.

A sea of colourful flowers fills the large glasshouse at PlentyFlora. The gerbera growing enterprise at Horohoro is thriving thanks to a good combination of knowledge, thermal heat and the wonder of producing a highly desirable commercial flower.

Connie and Harald Esendam, originally from Holland, had visited New Zealand in 1990 and came back to settle here permanently in 1995. Harald was working for Carter Holt Harvey with pine tree tissue culture.

The breeding of gerbera was Harald’s main focus of research and work in Holland in the 1980s. And when the time came to look for an alternative to pine tree work, it was obvious growing gerbera would be on the top of the list. When the large glasshouses in Horohoro were put up for sale 16 years ago, the timing was perfect.

By Christmas 2002, Connie and Harald had their first gerbera flowers and 14 years later the commercial growing operation operates smoothly and efficiently.

Optimum temperature

Gerbera need particular growing environment and the ability to use a geothermal energy source, available at the Horohoro site, means they can maintain the temperature of the glasshouse to the optimal minimum temperatures – 13 degrees Celsius is needed – which is especially important during the winter months. This gives them a constant supply of high quality flowers. Gerbera is a subtropical plant species originating in South Africa, so there is a need to create a similar climate to get the best results.

The geothermal bore produces 85 degree Celsius geothermal fluid, which is used to heat the glasshouses.

The 2500m2 glasshouse at PlentyFlora is fully mechanised and the environment monitored closely. Roof panels can be opened to control the humidity and roof curtains are also used when the weather becomes too hot for the flowers, and to retain heat at night.

“Flower growing is a global market,” says Harald.

Tissue culture

The plants are purchased from a gerbera breeding company in Holland. They send the tiny tissue culture plant to an operation in India, which produce plantlets in its laboratories. The tissue culture and plantlets are propagated in a sterile environment, which means they can cross country borders. In Auckland the rooted baby plantlets are grown on for about eight weeks before they are sent to PlentyFlora.

Eight weeks after potting into the glasshouse, the plants will begin producing flowers. Lifespan is two to three years so each year they plant 5000-7000 new plants, about 40 per cent of their 14,000 flowering gerbera are housed in the glasshouse.

Mini gerbera

PlentyFlora has two different sized flowers. The standard sized gerbera is 10cm-13 cm in diameter; and the mini-variety is 6cm-8 cm, which Harald says has been very successful with 70 per cent of growers in Holland now growing the mini.

“It is perfect for bouquet, corsage and wedding cakes and is proving very popular with our customers. “We believed the mini would work well in our markets and it has been the case more and more customers want mini gerbera as they do have a longer vase life.

“They are easier to grow, produce more flowers, less costs to the florists and it covers a range of different purposes – for example, on cakes, hairdos, corsages and wristbands.

“We are always market-driven. It would be easy to only grow four varieties, but we need a larger diversity in colour for our customers. We now have 60 different varieties.

“One of our strengths is we have a relationship with our customers and there is a direct feedback from the end user – the florist or any other buyer – and we can react accordingly and are able to service our customers well. All deliveries are overnight.”

Order by colour

During spring and summer PlentyFlora sends flowers to auction in Auckland and Wellington. But this adds time to the final delivery and often the flowers are re-boxed, which can result in damage to the flowers so they only send to auction when there is surplus supply.

Most of PlentyFlora’s customers are florists who send their request for the colours they require and their orders are sent direct from PlentyFlora by courier.

The internet has improved the links allowing customers to see actual colours and also cuts down on actual time from cut to display.

Harald and Connie have developed their own packaging to ensure the flowers are treated in the best possible way and ensuring the good quality arrives for the end user. The flowers are picked three times a week, individually sleeved and placed in the large chiller before the packing for customer takes place.


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