Rhubarb: the colder the better
Together with his brother, Arie Pieter van der Hoek owns a rhubarb farm in Heinenoord. Rhubarb is the main crop, but they also grow cherries in a greenhouse.
‘My father has a large arable farm. About fifteen years ago, my brother and I were given a small field of rhubarb, about half a hectare. Rhubarb is easy to multiply, which made it possible for us to expand. We’re now up to about ten hectares. At first I did this alongside my job, but we now make most of our living from it. It’s only in the quiet period, mainly in the second half of the year, that we do some other work.’
Goliath
The farm mostly grows Goliath rhubarb.
‘This is a rhubarb with a green stem,’ says Arie Pieter. ‘It’s mainly grown for the preserves industry. Rhubarb is grown outdoors and can keep producing for up to seven years. The outdoor rhubarb is harvested around mid-May. There is a second crop, but it’s usually not good enough to harvest, and this also places a burden on the plant. We’ve had a Belgian customer for our outdoor rhubarb since my father’s time. He uses it to make juice.’
Forced cultivation
Some of the rhubarb crop is forced.
‘That means that after two years we move the outdoor plant to the greenhouse,’ says Arie Pieter. ‘That doesn’t happen on its own; you have to take a lot of factors into account. The plant must be completely at rest in winter. What’s important here is that plants get cold enough: the colder the better. To keep an eye on this, we measure cold points after the plant dies back in September. For example: a night with 0 degrees in the soil scores 10 points. The plants can go into the greenhouse after about 350 cold points. This usually happens around January. The greenhouse is darkened and the heater is set to 20 degrees. After about four weeks the first rhubarb can be harvested from the greenhouse; we have a total of six or seven weeks of harvest. After the harvest the plants are worn out and have to be destroyed. This means that every year we have to create a new outdoor field to allow the process to run its course.
Gap in the market
Forced cultivation has enabled Arie and Pieter to fill a gap in the market.
‘This crop used to be more common in the area, but now it’s almost non-existent. You could say it’s a niche in the market. Greenhouse rhubarb is less tart and has a different colour. Outdoor rhubarb has a green stem, indoor rhubarb is red with yellow leaves. It’s the demand for this type that we’re responding to. All of the greenhouse rhubarb goes to Versland.’
Cherries and rhubarb for the fresh market
In addition to the Goliath, the company also grows cherries and rhubarb for the fresh food market on a small scale.
‘The cherries came to us by chance,’ says Arie Pieter. ‘We bought a fruit farm with a cherry greenhouse on it. We decided to carry on growing them. It’s a special kind of cherry, an early type. We use a very precise growing method to ensure that we deliver the season’s first cherries. We’ve also got a small piece of land with rhubarb for the fresh food market, a different type. That’s the rhubarb you see in the supermarket.’