Preparation

Your tulip bulbs often need a temperature treatment to ensure that they will grow optimally. In our own modern treatment rooms – of which we have more than 25 – we can treat your bulbs at a specific temperature. This allows us to influence the flowering date of your bulbs and suit your needs. For example, we can make sure that your tulips bloom during Christmas, (Chinese) New Year, Valentine’s Day, Easter, or International Women’s Day. We can cool or heat your bulbs with our computerised treatment systems in order to achieve the desired results. This allows us to supply you with high-quality bulbs throughout the year.  

Stage G

After the tulip bulbs are harvested in the summer, a new flower develops inside the bulb. This happens in different stages. First, the petals develop, then the stamens, and lastly the pistil. After this, the entire flower exists in embryo in the bulb. This is what we call ‘Stage G’. We take samples of the tulip bulbs of every stock number and examine them under a microscope. This way, we can determine if the bulb has reached Stage G. If it has, we register the date in the record system of our stock numbers. We can calculate the earliest possible flowering date and the necessary cooling treatment based on this date.

Cooling treatment tulips

Tulips must undergo a so-called cold period in order to develop long stems and to be able to flower. If the tulip bulbs are planted in an area with cold winters, they get a natural cold period. Tulip bulbs that are placed in a cooling room before the winter months can flower earlier than their natural flowering date. This is what we call forcing.

The tulips need to undergo a warm period prior to the cold period, so that the flower inside the tulip bulb can develop. This happens in a treatment room in which we heat the bulbs at a specific temperature until they have reached Stage G. After this, the cold period can begin.

If the tulip bulbs are going to be planted directly in the border soil in the greenhouse of the flower grower, we will generally give them a 5°C cooling treatment. The greenhouse temperature should be kept at 9°C so that the tulips can root well. This takes at least three weeks. After the tulips have rooted, the temperature can be raised to 18°C. The tulips will then bloom three to four weeks depending on the variety, season, etc.

If the tulip bulbs are going to planted in trays filled with soil or water and placed in a rooting room, we will give them a 9°C cooling treatment. After the rooting is complete and the cooling treatment is finished, the cases with rooted tulips can be placed in the greenhouse where the tulips will bloom.

We are capable of applying all possible cooling treatments of 9°C, 5°C, and 2°C, or a combination of these. We would be pleased to examine the best possible treatment for your bulbs together with you, while taking the local conditions, such as cooling facilities, greenhouse, soil temperature, and humidity, into account. Please contact us so we can check the possibilities for you.

Early flowering

We also supply tulip bulbs that are suitable for early flowering. These bulbs are from different areas, including France. It is usually hotter in France than in the Netherlands, which leads to a faster growth of the bulbs and an earlier harvest. We supply tulip bulbs that are grown under plastic foil as well. The plastic ensures that the tulips will bloom approximately two weeks earlier than normal, mostly in the beginning of December. If you are interested in bulbs for early flowering, please inquire with us about the availability.