Don’t serve your crop fast food: advice for fertilizer composition


The right amount and composition of fertilizer is crucial for growing plants. After working at Syngenta Flowers for over 40 years, Technical Specialist Ben Geijtenbeek knows what kind of ‘dinner’ crops love the best. In this regards, he knows one thing for sure: don’t serve your crops a fast food menu.

“Fertilizer is for a plant as a daily dinner for us”, says Ben. “The different elements as for instance calcium, potassium, magnesium and iron are the building blocks for the plant, and no fertilizer means no growth.”  In other words: bad fertilization, bad growth.

Single element fertilizers
Although there are several types of fertilizer available, Ben advices growers to use the premixed ones only for the simple and quick crops up to 10 weeks culture time.  For the others use the so called single element fertilizers as calcium nitrate or magnesium sulphate.

“Unlike the name, all fertilizers contain two elements, for instance calcium and nitrate. Those fertilizers give the best options for the control of the long term crops (> 10 weeks) as potplants like Cyclamen, Poinsettia and Dipladenia, biennals and perennials, winter crops as Pansy, Primula, Ranunculus, etc. Reason for this, is that with this composition the optimum requirement of the plants can be achieved most accurately, based on the available water quality, the needs of the grower, the specific crop and the season. "

Speaking about fertilizer, it’s all a matter of proportions and it is visible on the plants: “Plants don’t lie!”. “Out of experience, I can say that the common mistake made, is not enough fertilizer, and insufficient control on EC and pH and, many times, a too simple composition used. This is the main reason of yellowing leaves, stretched growth, lack of side shoots, resulting in a bad garden performance.”

Fast food
In order to get the best out of the plants, a tailor made advice is the best solution.  You can compare this with fast-food – we can all survive a certain time on it, but you’ll get a better condition when you adjust your meals on size, age, gender, health, taste and personal preferences. A good grower doesn’t give fast-food to his plants, but tries to adjust the amount and the balance to his/her specific crop and circumstances.”

Controllable and uncontrollable factors
Ben: “The knowledge of a grower in combination with good genetics make the success.” The best general advice Ben could give to bring the best out of annuals, is: “There is a long list of bad to uncontrollable growing factors in your greenhouse, such as light, temperature and humidity. Make sure that the biggest controllable factor – fertilization – is not out of scope. It is one of the most important tools to control quality.”