2014-06-30

Despite numerous financial and other challenges, one Queensland hydroponic rose grower is growing ‘perfect’ red roses in a state-of-the-art greenhouse environment.

By CHRISTINE BROWN-PAUL

Located in South East Queensland’s Gold Coast hinterland, the township of Kooralbyn—an Aboriginal name meaning ‘place of the copperhead snake’—is around 64 kilometres south of Brisbane and is part of the Scenic Rim local government area. The first European settlement in the area can be traced back to the 1830s when southern timber millers sought the quality hardwoods of the lower valleys. It was not until Australia’s first major land booms in the 1840s that free settler pastoralists migrated to the area. Kooralbyn subsequently became one of the region’s most significant pastoral estates, the land used largely for cattle grazing.

Today, Kooralbyn is home to around 2000 residents and to a flourishing hydroponic rose growing operation—Kooralbyn Roses. Around 350 metres above sea level, the 49ha property was once part of the old Cobb and Co coach route and still has today the restored holding yards. The 8km of maintained roads on the property lead to some hidden treasures of rare protected wildlife, waterfalls and creeks, including many camping, horse riding and bush walking trails.



A retired engineer, hydroponic rose grower Peter McKenna uses scientific methods at Kooralbyn Roses, which he has garnered during in depth-research and extensive overseas travels.

Former Secretary of the FAQI Flower Association of Queensland, owner grower Peter McKenna is a retired electrical engineer. Travelling the world, he learnt how others grew roses to suit their climate, and subsequently developed his own plan.

“I wrote the algorithms that were necessary to do the electronics to make it work,” he says.

“There’s an algorithm involved in everything, even your toaster’s got a little algorithm in it.”

Kooralbyn Roses specialises in red roses only and is renowned for its production of much-prized, long-stemmed red roses, with a production capability of around 400 bunches per week.

“The farm started various trials to find a profitable, saleable product. During the last five years and after considerable market research, we have solidly established our plan for the future,” Peter says.

“There is a clear opportunity to grow and sell dark red, long-stemmed roses at good profit.

“Our greenhouse production is roses—the Queensland market can never get enough red roses,” Peter says.

“The types of rose varieties we grow include Magic Red, a Rosen Tantau product from Germany; and Samurai, a Meilland product from France.  Both are good producers, but the Magic Red is less prone to disease,” he says.

“Our primary market is the many florist shops in Queensland.

“We provide to the contractors that pack and deliver to the various internet sales houses,” he says.

“We distribute through one wholesaler, Real Time Flowers, in Rocklea Brisbane.  We find the small commission charged well and truly offsets time taken in selling, taking calls, handling complaints and handling waste. We run ads in trade magazines and the like directing our customer to the wholesaler.”

Peak production demand for most rose growers is Valentine’s Day.

“Most other rose producers ramp up production for Valentine’s Day but this means that, at Christmas, you have to cut your bushes right back with the result that you have nothing to supply for six weeks before and after Valentine’s Day,” Peter says.

“Although we are always busy around Valentine’s Day, we also get plenty of sales before and after. We keep a few back so they arrive on the right day and we do get twice the price for Valentine’s Day roses.”



Kooralbyn Roses is a hydroponic rose growing facility using three state-of-the-art greenhouses.

In the greenhouse

Peter built the first greenhouse in January 2005, with a modest investment. Today, the business has three fully automated greenhouses.

“Our greenhouse system is state-of-the-art. We have many interstate and overseas visitors coming here who want to learn our methods of production,”  he says.

“We have travelled to Germany, Japan and the Netherlands to gain this knowledge.”

Growing roses in Queensland’s harsh climate presents its challenges.

“They are difficult to grow in our harsh conditions. Because the red rose is dark, it absorbs heat easily, thus burning the tip of the petal. The UV-B ray causes this heat,” Peter says.

“We use foggers to increase the humidity and allow the plants to transpire. It can also can reduce temperature in the greenhouse.”

Foggers are used to increase the humidity and allow the plants to transpire while an imported special laminated greenhouse film reduces harmful UV-B rays and protects the roses.

“We have imported from Israel a special laminated greenhouse film that reduces harmful UV-B rays. This film restricts the heat and protects the roses,” he says.

The second greenhouse was completed early in 2008. An extension of the first, it features a research and development exclusion bay to allow isolation for suitability tests.

“Our third greenhouse was completed in 2010. It is a larger structure, about 2500 m2.  It is, of course, ‘state-of-the-art’ and produces vibrant long stem red roses,” Peter says.

“We buy small roses, about 10cm high then plant and feed them in a hydroponic solution three to four times a day.

“We grow hydroponically, elevated on stands, in rows. Instead of the rose plant getting its food or nutrients from the soil, they are fed by nutrient-enriched water; as many times a day as needed.

Roses are planted in a substrate in a polystyrene broccoli box, four to a box, to support the plant and its roots. When the plant grows to a height of about 500mm, it is bent over the side of the box to allow photosynthesis to take place.

“We plant roses in a substrate, or media, in a polystyrene broccoli box, four to a box, to support the plant and its roots.  The substrate is a combination of cocopeat and coconut fibre,” he says.

“Most hydroponic systems in Europe have nearly all coconut husks and fibre, and very little cocopeat, to ensure that the substrate drains completely after each feed.  This gives air around the root system.

“In Queensland, we add cocopeat to retain some moisture so as to ensure we don’t cause stress to the plant on our very hot days.  We use a ratio of 75% fibre and 25% cocopeat,” Peter explains.

“When the plant grows to a height of about 500mm, we carefully bend it over the side of the styrene box. It becomes a skirt to allow photosynthesis to take place. Photosynthesis provides the food sugars to feed all plants.

“Water is collected from the greenhouse roof. We keep around 300,000 litres in tanks. We find roses operate best in water under a pH level of 5.5,” he says.

Peter says that because the skirt is below the box, the plant will try to produce and it will develop ‘bud eyes’ on either side of the bend.

“These will become long-stemmed roses. These roses are cut at the second full frond, for sale, and again below the cut, a new set of ‘bud eyes’ will appear and so the process is repeated again and again,” he says.

Light and fertigation

Peter says that an understanding of the role of light radiation as the main driver of plant transpiration is key.

“Light energy impinges on the plants’ leaves and warms them. The leaves respond by opening their stomata (under the leaf), exposing water to the atmosphere and this evaporates and cools the plant,” he says.

“If the sun is too intense and the plant cannot provide enough water to the leaves, then wilt will occur. The simple way to protect the plant from this is to provide shade. Note that air temperature and humidity have a minor influence, as compared with light intensity; and a plant can survive at much higher temperatures if some shading is provided.

“We provide an automatic solar curtain that will slide across to cover the rose plants. It is made with gaps in it to allow natural ventilation. The solar curtains are controlled by the light intensity in the greenhouse,” Peter says.

“In terms of fertigation, we like to feed at a pH of 5.5, which is quite acidic. At that pH, all the nutrients are easily taken up by the plant. We use a fertigation controller and small peristaltic pumps to correctly control the food requirements to each rose plant.”

Fertigation is achieved in a batch dosed tank.

“This method is simpler, has the potential for more buffering and manual intervention in the event of failure and is suited to a single feed recipe and common EC for the complete crop,” Peter says.

“It also gives more time for refilling and dosing the tank between irrigations and this does limit the number of zones (stations) that it can handle—we have four.

“This controller sequentially irrigates all stations in turn; one to four,” he says.

“We use a two-tank feeder system for the chemicals needed to provide the correct nutrients to the batch tank. Tank ‘A’ holds mainly calcium nitrate with a bit of iron chelate and a small amount of nitric acid, while Tank ‘B’ holds mainly MKP—magnesium sulphate, potassium nitrate, a little potassium sulphate and Nitric acid.  We also include the trace elements in Tank B.”

Challenges and rewards

Peter says that there are many challenges in growing hydroponic roses in Queensland, but none that aren’t normal in running a farm.

“A large head red rose is not easily grown in Queensland. The warmer climate prohibits this. We have developed a rose to suit our conditions; we have provided the necessary mechanical changes to our greenhouses to do this,” he says.

“The greatest issue is price. It is difficult to ask for a price that suits you if you don’t produce a consistently good product, reliably.

“In terms of pests, we don’t use IPM. Our main irritant is the Two Spotted Mite. It loves the high, warm areas on the rose bush while Phytoseiulus persimilis, a predatory mite, just loves the lower protected areas,” Peter says.

“Growing long-stemmed roses means the persimilis would need to get to the top of the rose plant, up to a metre—it doesn’t, so dies off from the lack of food while the mite thrives and multiplies.

“We actively scout, each day, to see the signs of mite activity and spot spray. If an outbreak occurs we will spray the house with a selection of miticides and vary them so the mite doesn’t become tolerant to just one pesticide or miticide,” he says.

Long-stemmed red roses are much prized and in demand, especially at peak periods such as Valentine’s Day.

Roses are sold in bulk in bunches of 10.  The yearly average price of $5-6 a bunch only increases around Valentine’s Day or Mother’s day.

“For the larger red rose, the market is supplied, unreliably, from South Africa or South America. We are providing our roses into this market at $15.40 per bunch, week in and week out. Our capacity has grown this year to 230,000 roses,” Peter says.

Peter says that contrary to the case in Europe where people use roses for household décor, in Australia, they are bought mostly as gifts. Low demand and high production cost means there is little profit for local growers and florists.

“Nobody’s making any money, the shopkeeper’s not making any money, the grower certainly is not making any money,” he said

“The wholesaler gets maybe 12 or 15%… and the punter’s whingeing because they’re not getting what they want… it’s hard work.”

Peter says the number of imported flowers is relatively low, but the average price is about 22 cents per stem.

“You have to think about how you could possibly make a living growing roses in Australia and getting 22 cents for them,” he said.

“If I grow about half a million red roses a year, and I got 22 cents from them, that would be $110,000.

“That wouldn’t even pay for the necessary nutrients for my plants to survive.”

Despite challenges, Peter says he loves what he does and that living in Kooralbyn is ideal.

Queensland’s Gold Coast hinterland and the township of Kooralbyn is part of the Scenic Rim local government area.

“We all talk about the monetary aspects of it but maybe people like to grow flowers,” he says.

“Maybe they like to live in a farm environment and send their children to schools where there’s no great deal of violence and people are happy little ducks.

“When you step out into the fresh air in Kooralbyn, it’s easy to see why. You look at the news in the morning and everybody’s having strife,” Peter says.

“Living here in Kooralbyn, it’s just perfect.”

About the author
Christine Brown-Paul is a Sydney-based journalist and a regular contributor to PH&G, with a special interest in the environment and sustainable technology. Email: c.brown.paul@gmail.com    Ω

PH&G July 2014 / Issue 145

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