At John and René van der Slot’s nursery the hyacinths are in rolling greenhouses. Their business is close to the sea in the Dutch Bulb Region which has traditionally been home to many bulb growers and forcers. There’s a strong sea breeze outdoors, but indoors – in the rolling greenhouse – the temperatures are pleasantly spring-like because the soil is heated. “We cover the soil with a layer of straw,” says John. “That acts as an insulating blanket.”
“Because the greenhouse is warm and light, the bulbs think it’s spring and start to flower,” explains John. As soon as all the hyacinths have been harvested, the rolling greenhouse is moved to the next section, where a new crop of bulbs is waiting. And then spring starts again!
“The nice thing about our business is that you can enjoy spring when it’s still winter,” says John van der Slot. First they simulate winter in the chiller. “I always think it’s a special moment when the chiller opens and you can see that the bulbs have formed roots and shoots. They’re doing it!”
“Our company really consists of two businesses: a cultivation nursery and a forcing nursery,” explains der Slot. First we grow the bulbs outdoors, where we do everything to produce a strong crop. After three of four years the bulbs are big enough to produce an attractive flower. At that point they’re moved to our forcing nursery.”
Unlike most seasonal flowers, it’s best not to trim hyacinths. The piece of bulb (at the bottom of the stem) ensures a longer vase life.